xref: /llvm-project/llvm/docs/CommandGuide/llvm-strip.rst (revision c975668ffc306719db3cbb08a00cb011fc212e13)

llvm-strip - object stripping tool
==================================

.. program:: llvm-strip

SYNOPSIS
--------

:program:`llvm-strip` [*options*] *inputs...*

DESCRIPTION
-----------

:program:`llvm-strip` is a tool to strip sections and symbols from object files.
If no other stripping or remove options are specified, :option:`--strip-all`
will be enabled.

By default, the input files are modified in-place. If "-" is specified for the
input file, the input is read from the program's standard input stream.

If the input is an archive, any requested operations will be applied to each
archive member individually.

The tool is still in active development, but in most scenarios it works as a
drop-in replacement for GNU's :program:`strip`.

GENERIC AND CROSS-PLATFORM OPTIONS
----------------------------------

The following options are either agnostic of the file format, or apply to
multiple file formats.

.. option:: --disable-deterministic-archives, -U

 Use real values for UIDs, GIDs and timestamps when updating archive member
 headers.

.. option:: --discard-all, -x

 Remove most local symbols from the output. Different file formats may limit
 this to a subset of the local symbols. For example, file and section symbols in
 ELF objects will not be discarded. Additionally, remove all debug sections.

.. option::  --enable-deterministic-archives, -D

 Enable deterministic mode when stripping archives, i.e. use 0 for archive member
 header UIDs, GIDs and timestamp fields. On by default.

.. option:: --help, -h

 Print a summary of command line options.

.. option::  --no-strip-all

 Disable :option:`--strip-all`.

.. option::  -o <file>

 Write output to <file>. Multiple input files cannot be used in combination
 with -o.

.. option:: --only-keep-debug

 Produce a debug file as the output that only preserves contents of sections
 useful for debugging purposes.

 For ELF objects, this removes the contents of `SHF_ALLOC` sections that are not
 `SHT_NOTE` by making them `SHT_NOBITS` and shrinking the program headers where
 possible.

.. option:: --regex

 If specified, symbol and section names specified by other switches are treated
 as extended POSIX regular expression patterns.

.. option:: --remove-section <section>, -R

 Remove the specified section from the output. Can be specified multiple times
 to remove multiple sections simultaneously.

.. option:: --strip-all-gnu

 Remove all symbols, debug sections and relocations from the output. This option
 is equivalent to GNU :program:`strip`'s ``--strip-all`` switch.

.. option:: --strip-all, -s

 For ELF objects, remove from the output all symbols and non-alloc sections not
 within segments, except for .gnu.warning, .ARM.attribute sections and the
 section name table.

 For COFF objects, remove all symbols, debug sections, and relocations from the
 output.

.. option:: --strip-debug, -d, -g, -S

 Remove all debug sections from the output.

.. option:: --strip-symbol <symbol>, -N

 Remove all symbols named ``<symbol>`` from the output. Can be specified
 multiple times to remove multiple symbols.

.. option:: --strip-unneeded

 Remove from the output all local or undefined symbols that are not required by
 relocations. Also remove all debug sections.

.. option:: --version, -V

 Display the version of the :program:`llvm-strip` executable.

.. option:: --wildcard, -w

  Allow wildcard syntax for symbol-related flags. On by default for
  section-related flags. Incompatible with --regex.

  Wildcard syntax allows the following special symbols:

  ====================== ========================= ==================
   Character              Meaning                   Equivalent
  ====================== ========================= ==================
  ``*``                  Any number of characters  ``.*``
  ``?``                  Any single character      ``.``
  ``\``                  Escape the next character ``\``
  ``[a-z]``              Character class           ``[a-z]``
  ``[!a-z]``, ``[^a-z]`` Negated character class   ``[^a-z]``
  ====================== ========================= ==================

  Additionally, starting a wildcard with '!' will prevent a match, even if
  another flag matches. For example ``-w -N '*' -N '!x'`` will strip all symbols
  except for ``x``.

  The order of wildcards does not matter. For example, ``-w -N '*' -N '!x'`` is
  the same as ``-w -N '!x' -N '*'``.

.. option:: @<FILE>

 Read command-line options and commands from response file `<FILE>`.

ELF-SPECIFIC OPTIONS
--------------------

The following options are implemented only for ELF objects. If used with other
objects, :program:`llvm-strip` will either emit an error or silently ignore
them.

.. option:: --allow-broken-links

 Allow :program:`llvm-strip` to remove sections even if it would leave invalid
 section references. Any invalid sh_link fields will be set to zero.

.. option:: --discard-locals, -X

 Remove local symbols starting with ".L" from the output.

.. option:: --keep-file-symbols

 Keep symbols of type `STT_FILE`, even if they would otherwise be stripped.

.. option:: --keep-section <section>

 When removing sections from the output, do not remove sections named
 ``<section>``. Can be specified multiple times to keep multiple sections.

.. option:: --keep-symbol <symbol>, -K

 When removing symbols from the output, do not remove symbols named
 ``<symbol>``. Can be specified multiple times to keep multiple symbols.

.. option::  --preserve-dates, -p

 Preserve access and modification timestamps in the output.

.. option:: --strip-sections

 Remove from the output all section headers and all section data not within
 segments. Note that many tools will not be able to use an object without
 section headers.

.. option:: -T

 Remove Swift symbols.

EXIT STATUS
-----------

:program:`llvm-strip` exits with a non-zero exit code if there is an error.
Otherwise, it exits with code 0.

BUGS
----

To report bugs, please visit <https://github.com/llvm/llvm-project/labels/tools:llvm-objcopy%2Fstrip>.

SEE ALSO
--------

:manpage:`llvm-objcopy(1)`