If no object files are listed as arguments, nm assumes a.out . The symbol value, in the radix selected by the following options, or hexadecimal by default. The symbol type. A The symbol s value is absolute, and will not be changed by further linking. The symbol is common.
Common symbols are uninitialized data.
When linking, multiple common symbols may appear with the same name. If the symbol is defined anywhere, the common symbols are treated as undefined references. For more details on common symbols, see the discussion of warn-common in Command line options in Using ld . The symbol is in the initialized data section. G The symbol is in an initialized data section for small objects.