syms(4)                          DG/UX 5.4.2                         syms(4)


NAME
       syms - common object file symbol table format

SYNOPSIS
       #include  <syms.h>

DESCRIPTION
       Common object files contain information to support symbolic software
       testing [see sdb(1)].  Line number entries [see linenum(4)] and
       extensive symbolic information permit testing at the C source level.
       Every object file's symbol table is organized as shown below.

         File name 1.
              Function 1.
                   Local symbols for function 1.
              Function 2.
                   Local symbols for function 2.
              ...
              Static externs for file 1.

         File name 2.
              Function 1.
                   Local symbols for function 1.
              Function 2.
                   Local symbols for function 2.
              ...
              Static externs for file 2.
         ...

         Defined global symbols.
         Undefined global symbols.

       The entry for a symbol is a fixed-length structure.  The members of
       the structure hold the name (null padded), its value, and other
       information.  The C structure is given below.

         #define  SYMNMLEN  8
         #define  FILNMLEN  14
         #define  DIMNUM    4

         struct  syment
         {
             union                         /* all ways to get symbol name */
             {
                 char        nname[SYMNMLEN]; /* symbol name */
                 struct
                 {
                     long    nzeroes;    /* == 0L when in string table */
                     long    noffset;    /* location of name in table */
                 } nn;
                 char        *nnptr[2];  /* allows overlaying */
             } n;
             long            nvalue;      /* value of symbol */
             short           nscnum;      /* section number */



Licensed material--property of copyright holder(s)                         1

syms(4)                          DG/UX 5.4.2                         syms(4)


             unsigned short  ntype;       /* type and derived type */
             char            nsclass;     /* storage class */
             char            nnumaux;     /* number of aux entries */
             char            npad1;       /* pad to 4 byte multiple */
             char            npad2;       /* pad to 4 byte multiple */
         };
         };
         };

         #define  nname    n.nname
         #define  nzeroes  n.nn.nzeroes
         #define  noffset  n.nn.noffset
         #define  nnptr    n.nnptr[1]

       Meaningful values and their explanations can be found in syms.h;.
       anyone who needs to interpret the entries should seek more
       information there.  Some symbols require more information than a
       single entry; they are followed by auxiliary entries that are the
       same size as a symbol entry.  The format follows:

         union auxent
         {
                struct
                {
                       long            xtagndx;
                       union
                       {
                              struct
                              {
                                       unsigned short  xlnno;
                                       unsigned short  xsize;
                              } xlnsz;
                              long     xfsize;
                       } xmisc;
                       union
                       {
                              struct
                              {
                                       long   xlnnoptr;
                                       long   xendndx;
                              }        xfcn;
                              struct
                              {
                                       unsigned short  xdimen[DIMNUM];
                              }        xary;
                       }               xfcnary;
                       unsigned short  xtvndx;
                       char   pad1;
                       char   pad2;
                }      xsym;
                struct
                {
                       char   xfname[FILNMLEN];
                }      xfile;



Licensed material--property of copyright holder(s)                         2

syms(4)                          DG/UX 5.4.2                         syms(4)


                 struct
                 {
                         long    xscnlen;
                         unsigned short  xnreloc;
                         unsigned short  xnlinno;
                 }       xscn;

                struct
                {
                       long            xtvfill;
                       unsigned short  xtvlen;
                       unsigned short  xtvran[2];
                }      xtv;
         };

       Indexes of symbol table entries begin at zero.

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

CAUTION
       Symbols declared as type long are recorded in the symbol table as
       type int.


































Licensed material--property of copyright holder(s)                         3