Scroll to navigation



llvm-cxxmap - Mangled name remapping tool


llvm-cxxmap [options] symbol-file-1 symbol-file-2


The llvm-cxxmap tool performs fuzzy matching of C++ mangled names, based on a file describing name components that should be considered equivalent.

The symbol files should contain a list of C++ mangled names (one per line). Blank lines and lines starting with # are ignored. The output is a list of pairs of equivalent symbols, one per line, of the form

<symbol-1> <symbol-2>

where <symbol-1> is a symbol from symbol-file-1 and <symbol-2> is a symbol from symbol-file-2. Mappings for which the two symbols are identical are omitted.


-remapping-file=file, -r=file
Specify a file containing a list of equivalence rules that should be used to determine whether two symbols are equivalent. Required. See REMAPPING FILE.

-output=file, -o=file
Specify a file to write the list of matched names to. If unspecified, the list will be written to stdout.

Produce a warning if there are multiple equivalent (but distinct) symbols in symbol-file-2.

Produce a warning if symbol-file-1 contains a symbol for which there is no equivalent symbol in symbol-file-2.


The remapping file is a text file containing lines of the form

fragmentkind fragment1 fragment2

where fragmentkind is one of name, type, or encoding, indicating whether the following mangled name fragments are <name>s, <type>s, or <encoding>s, respectively. Blank lines and lines starting with # are ignored.

For convenience, built-in <substitution>s such as St and Ss are accepted as <name>s (even though they technically are not <name>s).

For example, to specify that absl::string_view and std::string_view should be treated as equivalent, the following remapping file could be used:

# absl::string_view is considered equivalent to std::string_view
type N4absl11string_viewE St17basic_string_viewIcSt11char_traitsIcEE
# std:: might be std::__1:: in libc++ or std::__cxx11:: in libstdc++
name St St3__1
name St St7__cxx11


Symbol remapping is currently only supported for C++ mangled names following the Itanium C++ ABI mangling scheme. This covers all C++ targets supported by Clang other than Windows targets.


Maintained by the LLVM Team (


2003-2020, LLVM Project
2020-03-19 8