stfd(3)stfd(3)NAMEstfd - routines that provide access to per file descriptor section of
the symbol table
SYNOPSIS
#include <syms.h>
long st_currentifd(
void ); long st_ifdmax(
void ); void st_setfd(
long ifd ); long st_fdadd(
char *filename ); long st_symadd(
long iss,
long value,
long st,
long sc,
long freloc,
long index ); long st_auxadd(
AUXU aux ); long st_stradd(
char *cp ); long st_lineadd(
long line ); long st_pdadd(
long isym ); long st_ifd_pcfd(
pCFDR pcfd1 ); pCFDR st_pcfd_ifd(
long ifd ); pSYMR st_psym_ifd_isym(
long ifd,
long isym ); pAUXU st_paux_ifd_iaux(
long ifd,
long iaux ); pAUXU st_paux_iaux(
long iaux ); char *st_str_iss(
long iss ); char *st_str_ifd_iss(
long ifd,
long iss ); pPDR st_ppd_ifd_isym(
long ifd,
long isym ); char *st_malloc(
char *ptr ,
long *size,
long itemsize,
long baseitems );
DESCRIPTION
The stfd routines provide an interface to objects handled on a per file
descriptor (fd) level (for example, local symbols, auxiliaries, local
strings, line numbers, optimization entries, procedure descriptor
entries, and the file descriptors). These routines constitute a group
because they deal with objects corresponding to fields in the FDR
structure.
An fd routine can be activated by reading an existing one into memory
or by creating a new one. The compilation unit routines st_readbinary()
and st_readst() read file descriptors and their constituent parts into
memory from a symbol table on disk.
The st_fdadd() routine adds a file descriptor to the list of file
descriptors. The lang field is initialized from a user-specified global
st_lang that should be set to a constant designated for the language in
symconst.h. The fMerge field is initialized from the user-specified
global st_merge that specifies whether the file is to start with the
attribute of being able to be merged with identical files at load time.
The Bigendian field is initialized by the gethostsex() routine (see
gethostsex(3)), which determines the permanent byte ordering for the
auxiliary and line number entries for this file.
The st_fdadd() routine adds the null string to the new files string ta‐
ble that is accessible by the constant issNull (0). It also adds the
filename to the string table and sets the rss field. Finally, the cur‐
rent file is set to the newly added file so that later calls operate on
that file.
All routines for fd-level objects handle only the current file unless a
file index is specified. The current file can also be set with
st_setfd().
Programs can find the current file by calling st_currentifd(), which
returns the current index. Programs can find the number of files by
calling st_ifdmax(). The fd routines only require working with indices
to do most things. They allow more in-depth manipulation by allowing
users to get the compile-time file descriptor (CFDR) that contains mem‐
ory pointers to the per file tables (rather than indices or offsets
used in disk files). Users can retrieve a pointer to the CFDR by call‐
ing st_pcfd_ifd() with the index to the desired file. The inverse map‐
ping st_ifd_pcfd() exists, as well.
Each of fd's constituent parts has an add routine: st_symadd(),
st_stradd(), st_lineadd(), st_pdadd(), and st_auxadd(). The parameters
of the add routines correspond to the fields of the added object. The
st_pdadd() routine lets users fill in the isym field only. Further
information can be added by directly accessing the procedure descriptor
entry.
The add routines return an index that can be used to retrieve a pointer
to part of the desired object with one of the following routines:
st_psym_isym(), st_str_iss(), and st_paux_iaux(). Note: These routines
only return objects within the current file. The following routines
allow for file specification: st_psym_ifd_isym(), st_aux_ifd_iaux(),
and st_str_ifd_iss().
The st_ppd_ifd_isym() routine allows access to procedures through the
file index for the file where they occur and the isym field of the
entry that points at the local symbol for that procedure.
The return index from st_symadd() should be used to get a dense number
(see stcu(3)). That number should be the ucode block number for the
object that the symbol describes.
RESTRICTIONS
The interface will be added to incrementally, as needed.
SEE ALSOstcu(3), stfe(3)stfd(3)
