linenum(FP)                    6 January 1993                    linenum(FP)


 Name

    linenum - line number entries in a common object file

 Syntax


    #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(CP)).  Users can then reference line numbers when using the
    appropriate software test system (see sdb(CP)).  The structure of these
    line number entries follows:

       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:

       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

    a.out(FP), cc(CP), dbxtra(CP), codeview(CP), sdb(CP)