The meaning of lowercase symbol type of nm

[Nick Clifton]

Hi Peng,

> man nm says this.
> 
> o   The symbol type.  At least the following types are used; others
> are, as well, depending on the object file format.  If lowercase, the
> symbol is usually local;
> 
> What does "usually" mean here? Is there an example when it is not
> local yet it is still in lower case? Thanks.

There are a few cases where lower case letter might not mean that
the symbol is local.  For example:

     u 
  The symbol is a unique global symbol.  This is a GNU extension 
  to the standard set of ELF symbol bindings.  For such a symbol 
  the dynamic linker will make sure that in the entire process 
  there is just one symbol with this name and type in use.

    i
  For PE format files this indicates that the symbol is in a 
  section specific to the implementation of DLLs.  For ELF 
  format files this indicates that the symbol is an indirect 
  function.  This is a GNU extension to the standard set of 
  ELF symbol types.  It indicates a symbol which if referenced 
  by a relocation does not evaluate to its address, but instead 
  must be invoked at runtime.  The runtime execution will then 
  return the value to be used in the relocation.

Cheers
  Nick