3.5.2 HIDDEN

For ELF targeted ports, define a symbol that will be hidden and won't be exported. The syntax is HIDDEN(symbol = expression).

Here is the example from Simple Assignments, rewritten to use HIDDEN:

     HIDDEN(floating_point = 0);
     SECTIONS
     {
       .text :
         {
           *(.text)
           HIDDEN(_etext = .);
         }
       HIDDEN(_bdata = (. + 3) & ~ 3);
       .data : { *(.data) }
     }

In this case none of the three symbols will be visible outside this module.