linenum(4)                                             linenum(4)



     NAME
          linenum - line number entries in a common object file

     SYNOPSIS
          #include  <linenum.h>

     DESCRIPTION
          The C compiler generates an entry in the object file for
          each C source line on which a breakpoint is possible (when
          invoked with the -g option; see cc(1)).  Users can then
          reference line numbers when using the appropriate software
          test system (see sdb(1)).  The structure of these line
          number entries appears below.

          struct  lineno
          {
                  union
                  {
                         long     l_symndx ;
                         long     l_paddr ;
                  }               l_addr ;
                  unsigned short  l_lnno ;
          } ;

          Numbering starts with one for each function.  The initial
          line number entry for a function has llnno equal to zero,
          and the symbol table index of the function's entry is in
          lsymndx.  Otherwise, llnno is non-zero, and lpaddr is the
          physical address of the code for the referenced line.  Thus
          the overall structure is the following:

                    laddr                   llnno

                    function symtab index    0
                    physical address         line
                    physical address         line
                    ...

                    function symtab index    0
                    physical address         line
                    physical address         line
                    ...


     SEE ALSO
          cc(1), sdb(1), a.out(4).









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