llvm-objcopy - object copying and editing tool

Set section properties in the output of section <section> based on the specified <flag> values. Can be specified multiple times to update multiple sections.

Supported flag names are alloc, load, noload, readonly, exclude, debug, code, data, rom, share, contents, merge and strings. Not all flags are meaningful for all object file formats.

For ELF objects, the flags have the following effects:

• alloc = add the SHF_ALLOC flag.
• load = if the section has SHT_NOBITS type, mark it as a SHT_PROGBITS section.
• readonly = if this flag is not specified, add the SHF_WRITE flag.
• exclude = add the SHF_EXCLUDE flag.
• code = add the SHF_EXECINSTR flag.
• merge = add the SHF_MERGE flag.
• strings = add the SHF_STRINGS flag.
• contents = if the section has SHT_NOBITS type, mark it as a SHT_PROGBITS section.

For COFF objects, the flags have the following effects:

• alloc = add the IMAGE_SCN_CNT_UNINITIALIZED_DATA and IMAGE_SCN_MEM_READ flags, unless the load flag is specified.
• noload = add the IMAGE_SCN_LNK_REMOVE and IMAGE_SCN_MEM_READ flags.
• readonly = if this flag is not specified, add the IMAGE_SCN_MEM_WRITE flag.
• exclude = add the IMAGE_SCN_LNK_REMOVE and IMAGE_SCN_MEM_READ flags.
• debug = add the IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_DISCARDABLE and IMAGE_SCN_MEM_READ flags.
• code = add the IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE and IMAGE_SCN_MEM_READ flags.
• data = add the IMAGE_SCN_CNT_INITIALIZED_DATA and IMAGE_SCN_MEM_READ flags.
• share = add the IMAGE_SCN_MEM_SHARED and IMAGE_SCN_MEM_READ flags.

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

Remove all symbols, debug sections and relocations from the output. This option is equivalent to GNU :program:objcopy'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 and Mach-O objects, remove all symbols, debug sections, and relocations from the output.

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

Remove all debug sections from the output.

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

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

.. option:: --strip-symbols

Remove all symbols whose names appear in the file <filename>, from the output. In the file, each line represents a single symbol name, with leading and trailing whitespace ignored, as is anything following a '#'. Can be specified multiple times to read names from multiple files.

.. option:: --strip-unneeded-symbol

Remove from the output all symbols named <symbol> that are local or undefined and are not required by any relocation.

.. option:: --strip-unneeded-symbols

Remove all symbols whose names appear in the file <filename>, from the output, if they are local or undefined and are not required by any relocation. In the file, each line represents a single symbol name, with leading and trailing whitespace ignored, as is anything following a '#'. Can be specified multiple times to read names from multiple files.

.. option:: --strip-unneeded

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

.. option:: --update-section =

Replace the contents of the section <name> with contents from the file <file>. If the section <name> is part of a segment, the new contents cannot be larger than the existing section.

.. option:: --version, -V

Display the version of the :program:llvm-objcopy 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:: @

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-objcopy will either emit an error or silently ignore them.

.. option:: --add-symbol =[

Add a new symbol called <name> to the output symbol table, in the section named <section>, with value <value>. If <section> is not specified, the symbol is added as an absolute symbol. The <flags> affect the symbol properties. Accepted values are:

• global = the symbol will have global binding.
• local = the symbol will have local binding.
• weak = the symbol will have weak binding.
• default = the symbol will have default visibility.
• hidden = the symbol will have hidden visibility.
• protected = the symbol will have protected visibility.
• file = the symbol will be an STT_FILE symbol.
• section = the symbol will be an STT_SECTION symbol.
• object = the symbol will be an STT_OBJECT symbol.
• function = the symbol will be an STT_FUNC symbol.
• indirect-function = the symbol will be an STT_GNU_IFUNC symbol.

Additionally, the following flags are accepted but ignored: debug, constructor, warning, indirect, synthetic, unique-object, before.

Can be specified multiple times to add multiple symbols.

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

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

.. option:: --change-start , --adjust-start

Add <incr> to the program's start address. Can be specified multiple times, in which case the values will be applied cumulatively.

.. option:: --compress-debug-sections []

Compress DWARF debug sections in the output, using the specified format. Supported formats are zlib. Use zlib if <format> is omitted.

.. option:: --decompress-debug-sections

Decompress any compressed DWARF debug sections in the output.

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

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

.. option:: --extract-dwo

Remove all sections that are not DWARF .dwo sections from the output.

.. option:: --extract-main-partition

Extract the main partition from the output.

.. option:: --extract-partition

Extract the named partition from the output.

.. option:: --globalize-symbol

Mark any defined symbols named <symbol> as global symbols in the output. Can be specified multiple times to mark multiple symbols.

.. option:: --globalize-symbols

Read a list of names from the file <filename> and mark defined symbols with those names as global in the output. In the file, each line represents a single symbol, with leading and trailing whitespace ignored, as is anything following a '#'. Can be specified multiple times to read names from multiple files.

.. option:: --input-target , -I

Read the input as the specified format. See SUPPORTED FORMATS_ for a list of valid <format> values. If unspecified, :program:llvm-objcopy will attempt to determine the format automatically.

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

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

.. option:: --keep-global-symbol , -G

Make all symbols local in the output, except for symbols with the name <symbol>. Can be specified multiple times to ignore multiple symbols.

.. option:: --keep-global-symbols

Make all symbols local in the output, except for symbols named in the file <filename>. In the file, each line represents a single symbol, with leading and trailing whitespace ignored, as is anything following a '#'. Can be specified multiple times to read names from multiple files.

.. option:: --keep-section