xref: /llvm-project/llvm/docs/CommandGuide/llvm-strip.rst (revision c975668ffc306719db3cbb08a00cb011fc212e13)
1llvm-strip - object stripping tool
2==================================
3
4.. program:: llvm-strip
5
6SYNOPSIS
7--------
8
9:program:`llvm-strip` [*options*] *inputs...*
10
11DESCRIPTION
12-----------
13
14:program:`llvm-strip` is a tool to strip sections and symbols from object files.
15If no other stripping or remove options are specified, :option:`--strip-all`
16will be enabled.
17
18By default, the input files are modified in-place. If "-" is specified for the
19input file, the input is read from the program's standard input stream.
20
21If the input is an archive, any requested operations will be applied to each
22archive member individually.
23
24The tool is still in active development, but in most scenarios it works as a
25drop-in replacement for GNU's :program:`strip`.
26
27GENERIC AND CROSS-PLATFORM OPTIONS
28----------------------------------
29
30The following options are either agnostic of the file format, or apply to
31multiple file formats.
32
33.. option:: --disable-deterministic-archives, -U
34
35 Use real values for UIDs, GIDs and timestamps when updating archive member
36 headers.
37
38.. option:: --discard-all, -x
39
40 Remove most local symbols from the output. Different file formats may limit
41 this to a subset of the local symbols. For example, file and section symbols in
42 ELF objects will not be discarded. Additionally, remove all debug sections.
43
44.. option::  --enable-deterministic-archives, -D
45
46 Enable deterministic mode when stripping archives, i.e. use 0 for archive member
47 header UIDs, GIDs and timestamp fields. On by default.
48
49.. option:: --help, -h
50
51 Print a summary of command line options.
52
53.. option::  --no-strip-all
54
55 Disable :option:`--strip-all`.
56
57.. option::  -o <file>
58
59 Write output to <file>. Multiple input files cannot be used in combination
60 with -o.
61
62.. option:: --only-keep-debug
63
64 Produce a debug file as the output that only preserves contents of sections
65 useful for debugging purposes.
66
67 For ELF objects, this removes the contents of `SHF_ALLOC` sections that are not
68 `SHT_NOTE` by making them `SHT_NOBITS` and shrinking the program headers where
69 possible.
70
71.. option:: --regex
72
73 If specified, symbol and section names specified by other switches are treated
74 as extended POSIX regular expression patterns.
75
76.. option:: --remove-section <section>, -R
77
78 Remove the specified section from the output. Can be specified multiple times
79 to remove multiple sections simultaneously.
80
81.. option:: --strip-all-gnu
82
83 Remove all symbols, debug sections and relocations from the output. This option
84 is equivalent to GNU :program:`strip`'s ``--strip-all`` switch.
85
86.. option:: --strip-all, -s
87
88 For ELF objects, remove from the output all symbols and non-alloc sections not
89 within segments, except for .gnu.warning, .ARM.attribute sections and the
90 section name table.
91
92 For COFF objects, remove all symbols, debug sections, and relocations from the
93 output.
94
95.. option:: --strip-debug, -d, -g, -S
96
97 Remove all debug sections from the output.
98
99.. option:: --strip-symbol <symbol>, -N
100
101 Remove all symbols named ``<symbol>`` from the output. Can be specified
102 multiple times to remove multiple symbols.
103
104.. option:: --strip-unneeded
105
106 Remove from the output all local or undefined symbols that are not required by
107 relocations. Also remove all debug sections.
108
109.. option:: --version, -V
110
111 Display the version of the :program:`llvm-strip` executable.
112
113.. option:: --wildcard, -w
114
115  Allow wildcard syntax for symbol-related flags. On by default for
116  section-related flags. Incompatible with --regex.
117
118  Wildcard syntax allows the following special symbols:
119
120  ====================== ========================= ==================
121   Character              Meaning                   Equivalent
122  ====================== ========================= ==================
123  ``*``                  Any number of characters  ``.*``
124  ``?``                  Any single character      ``.``
125  ``\``                  Escape the next character ``\``
126  ``[a-z]``              Character class           ``[a-z]``
127  ``[!a-z]``, ``[^a-z]`` Negated character class   ``[^a-z]``
128  ====================== ========================= ==================
129
130  Additionally, starting a wildcard with '!' will prevent a match, even if
131  another flag matches. For example ``-w -N '*' -N '!x'`` will strip all symbols
132  except for ``x``.
133
134  The order of wildcards does not matter. For example, ``-w -N '*' -N '!x'`` is
135  the same as ``-w -N '!x' -N '*'``.
136
137.. option:: @<FILE>
138
139 Read command-line options and commands from response file `<FILE>`.
140
141ELF-SPECIFIC OPTIONS
142--------------------
143
144The following options are implemented only for ELF objects. If used with other
145objects, :program:`llvm-strip` will either emit an error or silently ignore
146them.
147
148.. option:: --allow-broken-links
149
150 Allow :program:`llvm-strip` to remove sections even if it would leave invalid
151 section references. Any invalid sh_link fields will be set to zero.
152
153.. option:: --discard-locals, -X
154
155 Remove local symbols starting with ".L" from the output.
156
157.. option:: --keep-file-symbols
158
159 Keep symbols of type `STT_FILE`, even if they would otherwise be stripped.
160
161.. option:: --keep-section <section>
162
163 When removing sections from the output, do not remove sections named
164 ``<section>``. Can be specified multiple times to keep multiple sections.
165
166.. option:: --keep-symbol <symbol>, -K
167
168 When removing symbols from the output, do not remove symbols named
169 ``<symbol>``. Can be specified multiple times to keep multiple symbols.
170
171.. option::  --preserve-dates, -p
172
173 Preserve access and modification timestamps in the output.
174
175.. option:: --strip-sections
176
177 Remove from the output all section headers and all section data not within
178 segments. Note that many tools will not be able to use an object without
179 section headers.
180
181.. option:: -T
182
183 Remove Swift symbols.
184
185EXIT STATUS
186-----------
187
188:program:`llvm-strip` exits with a non-zero exit code if there is an error.
189Otherwise, it exits with code 0.
190
191BUGS
192----
193
194To report bugs, please visit <https://github.com/llvm/llvm-project/labels/tools:llvm-objcopy%2Fstrip>.
195
196SEE ALSO
197--------
198
199:manpage:`llvm-objcopy(1)`
200