1C++FILT(1) GNU Development Tools C++FILT(1)
2
6 c++filt - Demangle C++ and Java symbols.
7
9 c++filt [-_|--strip-underscore]
10 [-n|--no-strip-underscore]
11 [-p|--no-params]
12 [-t|--types]
13 [-i|--no-verbose]
14 [-s format|--format=format]
15 [--help] [--version] [symbol...]
16
18 The C++ and Java languages provide function overloading, which means
19 that you can write many functions with the same name, providing that
20 each function takes parameters of different types. In order to be able
21 to distinguish these similarly named functions C++ and Java encode them
22 into a low-level assembler name which uniquely identifies each
23 different version. This process is known as mangling. The c++filt [1]
24 program does the inverse mapping: it decodes (demangles) low-level
25 names into user-level names so that they can be read.
26 Every alphanumeric word (consisting of letters, digits, underscores,
28 dollars, or periods) seen in the input is a potential mangled name. If
29 the name decodes into a C++ name, the C++ name replaces the low-level
30 name in the output, otherwise the original word is output. In this way
31 you can pass an entire assembler source file, containing mangled names,
32 through c++filt and see the same source file containing demangled
33 names.
34 You can also use c++filt to decipher individual symbols by passing them
36 on the command line:
37 c++filt <symbol>
39 If no symbol arguments are given, c++filt reads symbol names from the
41 standard input instead. All the results are printed on the standard
42 output. The difference between reading names from the command line
43 versus reading names from the standard input is that command line
44 arguments are expected to be just mangled names and no checking is
45 performed to separate them from surrounding text. Thus for example:
46 c++filt -n _Z1fv
48 will work and demangle the name to "f()" whereas:
50 c++filt -n _Z1fv,
52 will not work. (Note the extra comma at the end of the mangled name
54 which makes it invalid). This command however will work:
55 echo _Z1fv, | c++filt -n
57 and will display "f(),", i.e., the demangled name followed by a
59 trailing comma. This behaviour is because when the names are read from
60 the standard input it is expected that they might be part of an
61 assembler source file where there might be extra, extraneous characters
62 trailing after a mangled name. For example:
63 .type _Z1fv, @function
65
67 -_
68 --strip-underscore
69 On some systems, both the C and C++ compilers put an underscore in
70 front of every name. For example, the C name "foo" gets the low-
71 level name "_foo". This option removes the initial underscore.
72 Whether c++filt removes the underscore by default is target
73 dependent.
74 -n
76 --no-strip-underscore
77 Do not remove the initial underscore.
78 -p
80 --no-params
81 When demangling the name of a function, do not display the types of
82 the function's parameters.
83 -t
85 --types
86 Attempt to demangle types as well as function names. This is
87 disabled by default since mangled types are normally only used
88 internally in the compiler, and they can be confused with non-
89 mangled names. For example, a function called "a" treated as a
90 mangled type name would be demangled to "signed char".
91 -i
93 --no-verbose
94 Do not include implementation details (if any) in the demangled
95 output.
96 -s format
98 --format=format
99 c++filt can decode various methods of mangling, used by different
100 compilers. The argument to this option selects which method it
101 uses:
102 "auto"
104 Automatic selection based on executable (the default method)
105 "gnu"
107 the one used by the GNU C++ compiler (g++)
108 "lucid"
110 the one used by the Lucid compiler (lcc)
111 "arm"
113 the one specified by the C++ Annotated Reference Manual
114 "hp"
116 the one used by the HP compiler (aCC)
117 "edg"
119 the one used by the EDG compiler
120 "gnu-v3"
122 the one used by the GNU C++ compiler (g++) with the V3 ABI.
123 "java"
125 the one used by the GNU Java compiler (gcj)
126 "gnat"
128 the one used by the GNU Ada compiler (GNAT).
129 --help
131 Print a summary of the options to c++filt and exit.
132 --version
134 Print the version number of c++filt and exit.
135 @file
137 Read command-line options from file. The options read are inserted
138 in place of the original @file option. If file does not exist, or
139 cannot be read, then the option will be treated literally, and not
140 removed.
141 Options in file are separated by whitespace. A whitespace
143 character may be included in an option by surrounding the entire
144 option in either single or double quotes. Any character (including
145 a backslash) may be included by prefixing the character to be
146 included with a backslash. The file may itself contain additional
147 @file options; any such options will be processed recursively.
148
150 1. MS-DOS does not allow "+" characters in file names, so on MS-DOS
151 this program is named CXXFILT.
152
154 the Info entries for binutils.
155
157 Copyright (c) 1991-2013 Free Software Foundation, Inc.
158 Permission is granted to copy, distribute and/or modify this document
160 under the terms of the GNU Free Documentation License, Version 1.3 or
161 any later version published by the Free Software Foundation; with no
162 Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
163 Texts. A copy of the license is included in the section entitled "GNU
164 Free Documentation License".
165binutils-2.24 2019-07-25 C++FILT(1)