54e57c8145
This avoids errors or __DECONST() from places with higher WARNS levels. Adjust a local cache variable in ipcs to const as well to compile in the new world order. Suggested by: jhb Reviewed by: jhb, kib, brueffer (man)
222 lines
6.6 KiB
Groff
222 lines
6.6 KiB
Groff
.\" Copyright (c) 1980, 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)stab.5 8.1 (Berkeley) 6/5/93
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd June 10, 2010
|
|
.Dt STAB 5
|
|
.Os
|
|
.Sh NAME
|
|
.Nm stab
|
|
.Nd symbol table types
|
|
.Sh SYNOPSIS
|
|
.In stab.h
|
|
.Sh DESCRIPTION
|
|
The file
|
|
.In stab.h
|
|
defines some of the symbol table
|
|
.Fa n_type
|
|
field values for a.out files.
|
|
These are the types for permanent symbols (i.e., not local labels, etc.)
|
|
used by the old debugger
|
|
.Em sdb
|
|
and the Berkeley Pascal compiler
|
|
.Xr pc 1 .
|
|
Symbol table entries can be produced by the
|
|
.Pa .stabs
|
|
assembler directive.
|
|
This allows one to specify a double-quote delimited name, a symbol type,
|
|
one char and one short of information about the symbol, and an unsigned
|
|
long (usually an address).
|
|
To avoid having to produce an explicit label for the address field,
|
|
the
|
|
.Pa .stabd
|
|
directive can be used to implicitly address the current location.
|
|
If no name is needed, symbol table entries can be generated using the
|
|
.Pa .stabn
|
|
directive.
|
|
The loader promises to preserve the order of symbol table entries produced
|
|
by
|
|
.Pa .stab
|
|
directives.
|
|
As described in
|
|
.Xr a.out 5 ,
|
|
an element of the symbol table
|
|
consists of the following structure:
|
|
.Bd -literal
|
|
/*
|
|
* Format of a symbol table entry.
|
|
*/
|
|
|
|
struct nlist {
|
|
union {
|
|
const char *n_name; /* for use when in-core */
|
|
long n_strx; /* index into file string table */
|
|
} n_un;
|
|
unsigned char n_type; /* type flag */
|
|
char n_other; /* unused */
|
|
short n_desc; /* see struct desc, below */
|
|
unsigned n_value; /* address or offset or line */
|
|
};
|
|
.Ed
|
|
.Pp
|
|
The low bits of the
|
|
.Fa n_type
|
|
field are used to place a symbol into
|
|
at most one segment, according to
|
|
the following masks, defined in
|
|
.In a.out.h .
|
|
A symbol can be in none of these segments by having none of these segment
|
|
bits set.
|
|
.Bd -literal
|
|
/*
|
|
* Simple values for n_type.
|
|
*/
|
|
|
|
#define N_UNDF 0x0 /* undefined */
|
|
#define N_ABS 0x2 /* absolute */
|
|
#define N_TEXT 0x4 /* text */
|
|
#define N_DATA 0x6 /* data */
|
|
#define N_BSS 0x8 /* bss */
|
|
|
|
#define N_EXT 01 /* external bit, or'ed in */
|
|
.Ed
|
|
.Pp
|
|
The
|
|
.Fa n_value
|
|
field of a symbol is relocated by the linker,
|
|
.Xr ld 1
|
|
as an address within the appropriate segment.
|
|
.Fa N_value
|
|
fields of symbols not in any segment are unchanged by the linker.
|
|
In addition, the linker will discard certain symbols, according to rules
|
|
of its own, unless the
|
|
.Fa n_type
|
|
field has one of the following bits set:
|
|
.Bd -literal
|
|
/*
|
|
* Other permanent symbol table entries have some of the N_STAB bits set.
|
|
* These are given in <stab.h>
|
|
*/
|
|
|
|
#define N_STAB 0xe0 /* if any of these bits set, don't discard */
|
|
.Ed
|
|
.Pp
|
|
This allows up to 112 (7 \(** 16) symbol types, split between the various
|
|
segments.
|
|
Some of these have already been claimed.
|
|
The old symbolic debugger,
|
|
.Em sdb ,
|
|
uses the following n_type values:
|
|
.Bd -literal
|
|
#define N_GSYM 0x20 /* global symbol: name,,0,type,0 */
|
|
#define N_FNAME 0x22 /* procedure name (f77 kludge): name,,0 */
|
|
#define N_FUN 0x24 /* procedure: name,,0,linenumber,address */
|
|
#define N_STSYM 0x26 /* static symbol: name,,0,type,address */
|
|
#define N_LCSYM 0x28 /* .lcomm symbol: name,,0,type,address */
|
|
#define N_RSYM 0x40 /* register sym: name,,0,type,register */
|
|
#define N_SLINE 0x44 /* src line: 0,,0,linenumber,address */
|
|
#define N_SSYM 0x60 /* structure elt: name,,0,type,struct_offset */
|
|
#define N_SO 0x64 /* source file name: name,,0,0,address */
|
|
#define N_LSYM 0x80 /* local sym: name,,0,type,offset */
|
|
#define N_SOL 0x84 /* #included file name: name,,0,0,address */
|
|
#define N_PSYM 0xa0 /* parameter: name,,0,type,offset */
|
|
#define N_ENTRY 0xa4 /* alternate entry: name,linenumber,address */
|
|
#define N_LBRAC 0xc0 /* left bracket: 0,,0,nesting level,address */
|
|
#define N_RBRAC 0xe0 /* right bracket: 0,,0,nesting level,address */
|
|
#define N_BCOMM 0xe2 /* begin common: name,, */
|
|
#define N_ECOMM 0xe4 /* end common: name,, */
|
|
#define N_ECOML 0xe8 /* end common (local name): ,,address */
|
|
#define N_LENG 0xfe /* second stab entry with length information */
|
|
.Ed
|
|
.Pp
|
|
where the comments give
|
|
.Em sdb
|
|
conventional use for
|
|
.Pa .stab
|
|
.Fa s
|
|
and the
|
|
.Fa n_name ,
|
|
.Fa n_other ,
|
|
.Fa n_desc ,
|
|
and
|
|
.Fa n_value
|
|
fields
|
|
of the given
|
|
.Fa n_type .
|
|
.Em Sdb
|
|
uses the
|
|
.Fa n_desc
|
|
field to hold a type specifier in the form used
|
|
by the Portable C Compiler,
|
|
.Xr cc 1 ;
|
|
see the header file
|
|
.Pa pcc.h
|
|
for details on the format of these type values.
|
|
.Pp
|
|
The Berkeley Pascal compiler,
|
|
.Xr pc 1 ,
|
|
uses the following
|
|
.Fa n_type
|
|
value:
|
|
.Bd -literal
|
|
#define N_PC 0x30 /* global pascal symbol: name,,0,subtype,line */
|
|
.Ed
|
|
.Pp
|
|
and uses the following subtypes to do type checking across separately
|
|
compiled files:
|
|
.Bd -unfilled -offset indent
|
|
1 source file name
|
|
2 included file name
|
|
3 global label
|
|
4 global constant
|
|
5 global type
|
|
6 global variable
|
|
7 global function
|
|
8 global procedure
|
|
9 external function
|
|
10 external procedure
|
|
11 library variable
|
|
12 library routine
|
|
.Ed
|
|
.Sh SEE ALSO
|
|
.Xr as 1 ,
|
|
.Xr ld 1 ,
|
|
.Xr a.out 5
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
file appeared in
|
|
.Bx 4.0 .
|
|
.Sh BUGS
|
|
More basic types are needed.
|