llvm-project/llvm/docs/CommandGuide/llvm-cxxmap.rst

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llvm-cxxmap - Mangled name remapping tool
=========================================
.. program:: llvm-cxxmap
SYNOPSIS
--------
:program:`llvm-cxxmap` [*options*] *symbol-file-1* *symbol-file-2*
DESCRIPTION
-----------
The :program:`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
.. code-block:: none
<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
-------
.. program:: llvm-cxxmap
.. option:: -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 :ref:`remapping-file`.
.. option:: -output=file, -o=file
Specify a file to write the list of matched names to. If unspecified, the
list will be written to stdout.
.. option:: -Wambiguous
Produce a warning if there are multiple equivalent (but distinct) symbols in
*symbol-file-2*.
.. option:: -Wincomplete
Produce a warning if *symbol-file-1* contains a symbol for which there is no
equivalent symbol in *symbol-file-2*.
.. _remapping-file:
REMAPPING FILE
--------------
The remapping file is a text file containing lines of the form
.. code-block:: none
fragmentkind fragment1 fragment2
where ``fragmentkind`` is one of ``name``, ``type``, or ``encoding``,
indicating whether the following mangled name fragments are
<`name <http://itanium-cxx-abi.github.io/cxx-abi/abi.html#mangle.name>`_>s,
<`type <http://itanium-cxx-abi.github.io/cxx-abi/abi.html#mangle.type>`_>s, or
<`encoding <http://itanium-cxx-abi.github.io/cxx-abi/abi.html#mangle.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 <http://itanium-cxx-abi.github.io/cxx-abi/abi.html#mangle.source-name>`_>:
.. code-block:: none
# 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:
.. code-block:: none
# 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.