LLVM-CXXMAP(1)

🎀 LLVM-CXXMAP(1) 🎀

okay so this is the LLVM manual page for llvm-cxxmap, and bestie, it's literally the mangled name remapping tool 💅. You're in the LLVM manual fam now, no cap 🫶.

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✨ NAME ✨

llvm-cxxmap — the mangled name remapping tool, periodt. 👑

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🦋 SYNOPSIS 🦋

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

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🌸 DESCRIPTION 🌸

okay so llvm-cxxmap does fuzzy matching of C++ mangled names 😭✨. The matching is based on a file that describes which name components should be considered equivalent — that file is kind of the main character here.

The symbol files should contain a list of C++ mangled names, one per line. Blank lines and lines starting with # are ignored, yes even here 🫶. The output is a list of pairs of equivalent symbols, one per line, and it looks like this:

<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 where the two symbols are identical are omitted — not me being lazy, the tool does that 💀.

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💖 OPTIONS 💖

• -remapping-file=file, -r=file — point this at a file containing a list of equivalence rules that should be used to determine whether two symbols are equivalent. This one is required, bestie 😭. See REMAPPING FILE below.
• -output=file, -o=file — where to write the list of matched names. If unspecified, the list gets 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 😬.

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🌈 REMAPPING FILE 🌈

The remapping file is a text file containing lines that look like this:

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. 💀

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👑 AUTHOR 👑

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

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🎀 COPYRIGHT 🎀

2003-2025, LLVM Project

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🌸 aaaand that's the whole vibe! This page is LLVM-CXXMAP(1) from the LLVM manual source/version, section 19, dated 2025-01-17. bye bestie, go remap those mangled names 💅✨