LLVM-OTOOL(1) General Commands Manual LLVM-OTOOL(1)

llvm-otool - the otool-compatible command line parser for llvm-objdump

llvm-otool [ option ... ] [ file ... ]

The command line shim llvm-otool takes all the same options as the original otool(1) command and executes an equivalent objdump(1) command. Its original intent was to ease changing usage over from otool(1) to the LLVM-based open source objdump(1) command with similar functionality. However, objdump(1) prefers different usage, with different behavior semantics and different output requirements. objdump(1) is no longer the preferred tool for inspecting modern Mach-O binaries. The llvm-otool command-line shim remains behind so that people who prefer to use the open source objdump(1) tool with otool-style semantics can continue to do so, mostly to support scripts or other tools that expect idiosyncrasies specific to that usage.

By default, llvm-otool will invoke the original otool(1) functionality, meaning general usage such as the following will be executed via otool-classic as explained in the otool-classic(1) manual.

% otool -hv file

The unambiguous invocation of otool(1) can be found as otool-classic(1) and typically will be run by using the xcrun(1) utility:

% xcrun otool-classic -hv file

One can invoke objdump(1) in "otool compatibility" mode by calling llvm-otool(1) with the -objdump flag:

% otool -objdump -hv file
You can also invoke objdump(1) directly on the command line using LLVM-native options:
% xcrun objdump --macho --private-header file
-objdump
This is a synonym for -object-tool-path objdump, described below.
-object-tool-path tool
After parsing the otool arguments, execute the command indicated by tool. This value defaults to "otool-classic". If the specified tool contains the string "otool" in its name, the tool will be executed with the original unmodified arguments to llvm-otool(1), otherwise the arguments will be translated into llvm-style arguments as explained below.
-show-objdump-command
Print the command that llvm-otool(1) will execute. This is useful for seeing how comnand-line options were transformed.

Many of the older options in otool(1) are obsolete as they print parts of the object file that are no longer in use. When translating options for objdump(1), obsolete options will produce a warning, and the option will be ignored. If no valid equivalent options are given then usage message from objdump(1) will be printed when executed.

The archive member syntax of arguments of the form libx.a(foo.o), is not supported. Which is the same as if the -m option is always used.

When doing disassembly the default is to not print the opcode bytes of the instructions even for 32-bit ARM. To get the opcode bytes printed for ARM the otool(1) option -j needs to be used.

There are some whitespace and capitalization differences in the output of the otool(1) and objdump(1) commands in some cases; the objdump(1) command is not meant to produce the exact same output as otool(1) in all cases even where the functionality is very similar.

Below is the list of otool(1) options and the specific objdump(1) option to print the same information. To use these options with objdump(1) the --macho option must be used.
-f
The objdump(1) option to display the universal headers is --universal-headers.
-a
The objdump(1) --archive-headers will print the archive header, if the file is an archive. To get the offsets to the archive headers that would be printed with the otool(1) -aV options, the objdump(1) --archive-member-offsets can be added.
-h
The objdump(1) option to display the Mach header is --private-header.
-l
The objdump(1) option to display the load commands is --private-headers. This implies the -h option, as --private-headers always displays the Mach header.
-L
The objdump(1) option to display the names and version numbers of the shared libraries that the object file uses, as well as the shared library ID if the file is a shared library is --dylibs-used.
-D
The objdump(1) option to display just the install name of a shared library is --dylib-id.
-t
The objdump(1) option to display the contents of the (__TEXT,__text) section is to use the --section __TEXT,__text option. If disassembly is wanted as with the -tv otool(1) options then the objdump(1) --disassemble is used. By default objdump(1) also symbolically disassembles the operands as the otool(1) -tV options will do. If this is not wanted then the objdump(1) --no-symbolic-operands option can be used.
-x
The objdump(1) option to display the contents of every __text section defined in a Mach-O file is --section ,__text. Note that an empty segment name means all segments. If disassembly is wanted as with the -xv otool(1) options then objdump(1) --disassemble-all is used. By default objdump(1) also symbolically disassembles the operands as the otool(1) -xV options will do. If this is not wanted then the objdump(1) --no-symbolic-operands option can be used.
-p name
The objdump(1) option to start the disassembly from symbol name is --dis-symname name.
-s segname sectname
The objdump(1) option to display the contents of the section (segname,sectname) is --section [segname,]sectname where the segname is optional and all segments will be searched for a matching sectname.
-d
The objdump(1) option to display the contents of the (__DATA,__data) section is to use the --section __DATA,__data option.
-o
The objdump(1) option to display the contents of the __OBJC segment used by the Objective-C run-time system is --objc-meta-data.
-r
The objdump(1) option to display the relocation entries is --reloc. Note that the default relocation entry format is different between objdump(1) and otool(1). When --reloc is combined with the --macho option, objdump(1) will display the relocation entries in the classic otool(1) format.
-S
There is no objdump(1) option to display the contents of the `__.SYMDEF' file, if the file is an archive. For that use llvm-nm(1) with the --print-armap option.
-I
The objdump(1) option to display the indirect symbol table is --indirect-symbols.
-G
The objdump(1) option to display the data in code table is --data-in-code.
-v
For objdump(1) verbose output is the default and to get non-verbose output the option --non-verbose is used.
-V
For objdump(1) displaying the disassembled operands symbolically is the default and to get non-symbolic operands with disassembly the option --no-symbolic-operands is used.
-X
The objdump(1) option to not print leading addresses or headers with disassembly of sections is --no-leading-addr.
-mcpu=arg
The objdump(1) option when doing disassembly using the llvm disassembler to use the cpu arg. is the --mcpu=arg option.
-j
The objdump(1) prints the opcode bytes of the instructions when doing disassembly by default and is turned off with the option --no-show-raw-insn.
-P
The objdump(1) option to print the info plist section, (__TEXT,__info_plist), as strings is --info-plist.
-C
The objdump(1) option to display the linker optimization hints is --link-opt-hints.
-arch arch_type
The objdump(1) options to specifies the architectures to operate on are the --arch arch_type options.
--version
The objdump(1) option to display the llvm-otool(1) version information and the objdump(1) version information is --version.

-T
There is no objdump(1) option to display the table of contents for a dynamically linked shared library, as this table is obsolete and no longer produced by the tools.
-M
There is no objdump(1) option to display the module table of a dynamically linked shared library, as this table is obsolete and no longer produced by the tools.
-R
There is no objdump(1) option to display the reference table of a dynamically linked shared library, as this table is obsolete and no longer produced by the tools.
-H
There is no objdump(1) option to display the two-level namespace hints table, as this table is obsolete and no longer produced by the tools.
-c
There is no objdump(1) option to display the argument strings (argv[] and envp[]) from a core file.
-m
There is no objdump(1) option to not assume to the archive(member) syntax as that is the default. And the archive(member) syntax is not supported as file arguments with objdump(1).
-B
There is no objdump(1) option to force Thumb disassembly on ARM objects.
-q
There is no objdump(1) option to use the llvm disassembler when doing disassembly as this is the default.
-Q
There is no objdump(1) option to use the otool(1) disassembler when doing disassembly as only the llvm disassembler is used.
-i
There is no objdump(1) option to display the shared library initialization table, as this table is obsolete and no longer produced by the tools.
-function_offsets
There is no objdump(1) option when doing disassembly to print the decimal offset from the last label printed.

otool-classic(1), llvm-objdump(1)
July 31, 2018 Apple Inc.