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NM(1) General Commands Manual NM(1)

nm - display name list (symbol table)

llvm-nm [ -agnoprumxjlPA ] [ - ] [ -t format ] [[ -arch arch_flag ]...] [ file ... ] [ -s segname sectname ]

nm-classic [ -agnoprumxjlfPA [ s segname sectname ]] [ - ] [ -t format ] [[ -arch arch_flag ]...] [ file ... ]

As of Xcode 8.0 the default nm(1) tool is llvm-nm(1). For the most part nm(1) and llvm-nm(1) have the same options; notable exceptions include -f, -s, and -L as described below. This document explains options common between the two commands as well as some historically relevant options supported by nm-classic(1). More help on options for llvm-nm(1) is provided when running it with the --help option.

nm displays the name list (symbol table of nlist structures) of each object file in the argument list. In some cases, as with an object that has had strip(1) with its -T option used on the object, that can be different than the dyld information. For that information use dyldinfo(1).

If an argument is an archive, a listing for each object file in the archive will be produced. File can be of the form libx.a(x.o), in which case only symbols from that member of the object file are listed. (The parentheses have to be quoted to get by the shell.) If no file is given, the symbols in a.out are listed.

Each symbol name is preceded by its value (blanks if undefined). Unless the -m option is specified, this value is followed by one of the following characters, representing the symbol type: U (undefined), A (absolute), T (text section symbol), D (data section symbol), B (bss section symbol), C (common symbol), - (for debugger symbol table entries; see -a below), S (symbol in a section other than those above), or I (indirect symbol). If the symbol is local (non-external), the symbol's type is instead represented by the corresponding lowercase letter. A lower case u in a dynamic shared library indicates a undefined reference to a private external in another module in the same library.

If the symbol is a Objective-C method, the symbol name is ±[Class_name(category_name) method:name:], where `+' is for class methods, `-' is for instance methods, and (category_name) is present only when the method is in a category.

The output is sorted alphabetically by default.

Options are:

Display all symbol table entries, including those inserted for use by debuggers.
Display only global (external) symbols.
Sort numerically rather than alphabetically.
Prepend file or archive element name to each output line, rather than only once.
Don't sort; display in symbol-table order.
Sort in reverse order.
Display only undefined symbols.
Don't display undefined symbols.
Display the N_SECT type symbols (Mach-O symbols) as (segment_name, section_name) followed by either external or non-external and then the symbol name. Undefined, common, absolute and indirect symbols get displayed as (undefined), (common), (absolute), and (indirect), respectively. Other symbol details are displayed in a human-friendly manner, such as "[no dead strip]". nm will display the referenced symbol for indirect symbols and will display the name of the library expected to provide an undefined symbol. See nlist(3) and <mach-o/nlist.h> for more information on the nlist structure.
Display the symbol table entry's fields in hexadecimal, along with the name as a string.
Just display the symbol names (no value or type).
List only those symbols in the section (segname,sectname). For llvm-nm(1) this option must be last on the command line, and after the files.
List a pseudo symbol .section_start if no symbol has as its value the starting address of the section. (This is used with the -s option above.)
Specifies the architecture, arch_type, of the file for nm(1) to operate on when the file is a universal file (see arch(3) for the currently known arch_types). The arch_type can be "all" to operate on all architectures in the file. The default is to display the symbols from only the host architecture, if the file contains it; otherwise, symbols for all architectures in the file are displayed.
-f format
For llvm-nm(1) this specifies the output format. Where format can be bsd, sysv, posix or darwin.
For nm-classic(1) this displays the symbol table of a dynamic library flat (as one file not separate modules). This is obsolete and not supported with llvm-nm(1).
Write the pathname or library name of an object on each line.
Write information in a portable output format.
For the -P output, write the numeric value in the specified format. The format shall be dependent on the single character used as the format option-argument:
The value shall be written in decimal (default).
The value shall be written in octal.
The value shall be written in hexadecimal.
Display the symbols in the bitcode files in the (__LLVM,__bundle) section if present instead of the object's symbol table. For nm-classic(1) this is the default if the object has no symbol table and an (__LLVM,__bundle) section exists. This option is not supported by llvm-nm(1) where displaying llvm bitcode symbols is the default behavior.

ar(1), ar(5), Mach-O(5), stab(5), nlist(3), dyldinfo(1)

Displaying Mach-O symbols with -m is too verbose. Without the -m, symbols in the Objective-C sections get displayed as an `s'.

December 13, 2018 Apple, Inc.