LINENUM(4)           INTERACTIVE UNIX System           LINENUM(4)



          NAME
               linenum - line number entries in a common object file

          SYNOPSIS
               #include  <linenum.h>

          DESCRIPTION
               The cc command 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 l_lnno equal to zero,
               and the symbol table index of the function's entry is in
               l_symndx.  Otherwise, l_lnno is non-zero, and l_paddr is the
               physical address of the code for the referenced line.  Thus
               the overall structure is the following:

                         l_addr                   l_lnno

                         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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