---
name: "llvm-cxxmap-18"
section: "1"
platform: "linux"
package: "llvm-18"
version: "1:18.1.8-18+b1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/llvm-cxxmap-18"
---

# llvm-cxxmap-18(1)

Mangled name remapping tool

## NAME

llvm-cxxmap - Mangled name remapping tool

## SYNOPSIS

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

## DESCRIPTION

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.

## OPTIONS

- **-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.

- **-Wambiguous**

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

- **-Wincomplete**

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

## REMAPPING FILE

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.

Unmangled C names can be expressed as an **encoding** that is a (length-prefixed) \<*source-name*\>:

```
# C function "void foo_bar()" is remapped to C++ function "void foo::bar()".
encoding 7foo_bar _Z3foo3barv
```

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
```

**NOTE:**

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.

## AUTHOR

Maintained by the LLVM Team (https://llvm.org/).

## COPYRIGHT

2003-2025, LLVM Project