stio.3

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 3 代码 · 共 135 行

.TH stio 3 RISC
.SH Name
st_readbinary, st_readst, st_writebinary, st_writest \- routines that provide a binary read/write interface to the MIPS symbol table
.SH Syntax
.nf
.B #include <syms.h>
.PP
.ft B
long st_readbinary (filename, how)
char *filename;
char how;
.PP
.ft B
long st_readst (fn, how, filebase, pchdr, flags)
long fn;
char how;
long filebase;
pCHDRR pchdr;
long flags;
.PP
.ft B
void st_writebinary (filename, flags)
char *filename;
long flags;
.PP
.ft B
void st_writest (fn, flags)
long fn;
long flags;
.PP
.fi
.ft R
.br
.SH Description
.PP
The CHDRR structure (see 
.B cmplrs/stsupport.h 
and the 
.MS stcu 3 ).
represents a symbol table in memory.  A new CHDRR can be created by reading 
a symbol table in from disk. The
.I st_readbinary
and
.I st_readst
routines read a symbol table in from disk.
.PP
The routine
.I st_readbinary\fR
takes the file name of the symbol table and assumes the symbol table header
.I (HDRR
in 
.B sym.h
occurs at the beginning of the file. The
.I st_readst
assumes that its file number references a file positioned at the 
beginning of the symbol table header and that the
.I filebase
parameter specifies where the object or symbol table file is based (for
example,
non-zero for archives).
.PP
The second parameter to the read routines can be r for read only or a 
for appending to the symbol table. Existing local symbol, line,
procedure, auxiliary, optimization, and local string tables 
cannot be appended. If they
didn't exist on disk, they can be created. This restriction stems from the
allocation algorithm for those symbol table sections when read in from disk
and follows the standard pattern for building the symbol table.
.PP
The symbol table can be read incrementally.  If 
.I pchdr is zero, 
.I st_readst 
assumes that a symbol table has not been read yet; therefore,
it reads in the symbol table header and file descriptors.  The 
.I flags
argument is a bit mask that defines what other tables should be read.  
The
.I t_p* 
constants for each table, defined in stsupport.h, can be ORed.  If 
\fIflags\fR equals -1, all tables are read.  If 
.I pchdr 
is set,
the tables specified by 
.I flags 
are added to the tables that have already been read.  The
.I pchdr's value can be taken from 
.I st_current_pchdr.  See 
.MS stcu 3.
.PP
Line number entries are encoded on disk; the read routines expand them
to longs.  
.PP
If the version stamp is out of date, a warning message is issued to stderr.
If the magic number in the HDRR is incorrect, 
.I st_error 
is called. All other errors cause the read routines to read non-zero; 
otherwise, a zero is returned.
.PP
The routines
.I st_writebinary
and
.I st_writest
are symmetric to the read routines, excluding the 
.I how 
and 
.I pchdr
parameters. The 
.I flags 
parameter is a bit mask that defines what table should 
be written.  The
.I st_p* 
constants for each table, defined in
.I stsupport.h,
can be ORed. If 
.I flags
equals -1, all tables are written.
.PP
The write routines write sections of the table in the approved
order, as specified in the link editor 
.MS ld 1 
specification.
.PP
Line numbers are compressed on disk.  
.PP
The write routines start all sections of the symbol
table on four-byte boundaries.
.PP
If the write routines encounter an error, 
.I st_error 
is called. After writing the symbol table, further access to the table 
by other routines is undefined.
.SH See Also
stcu(3), stfe(3), stfd(3), sym.h(5), sterror(5)
stsupport.h(5)