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/* flags.c -- Flag support for Khepera
* Created: Sat Mar 23 10:11:52 1996 by faith@cs.unc.edu
* Revised: Fri Jun 20 17:23:46 1997 by faith@acm.org
* Copyright 1994, 1995, 1996, 1997 Rickard E. Faith (faith@acm.org)
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Library General Public License as published
* by the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* $Id: flags.c,v 1.3 1997/06/21 01:05:12 faith Exp $
*
* \section{Flag Support}
*
* \intro These routines provide low-level support for run-time program
* flow control. The mechanism used is similar to that used for debugging
* messages. A set of global flags are maintained using "#define"
* statements. These flags are assumed to be 32-bit integers, the top two
* bits of which are used to select one of four sets of debugging lags.
* Each set, therefore, has 30 bits of flag information. For convenience,
* each flag can be given a unique name, so that flags can be set easily
* with command-line options.
* */
#include "maaP.h"
#define TEST(flags,var) (((flags)>>31) \
? (((flags)>>30) \
? ((var[3] & (flags)) << 2) \
: ((var[2] & (flags)) << 2)) \
: (((flags)>>30) \
? ((var[1] & (flags)) << 2) \
: ((var[0] & (flags)) << 2)))
static hsh_HashTable hash;
static flg_Type setFlags[4];
static flg_Type usedFlags[4];
/* |_flg_exists| returns non-zero if |flag| has been associated with a name
(using the |flg_register| function). */
static int _flg_exists( flg_Type flag )
{
return TEST( flag, usedFlags );
}
/* |flg_name| returns a pointer to the name that was associated with the
|flag|. */
const char *flg_name( flg_Type flag )
{
hsh_Position position;
void *key;
void *datum;
HSH_ITERATE( hash, position, key, datum ) {
if (flag == (flg_Type)datum) {
HSH_ITERATE_END( hash );
return key;
}
}
return "unknown flag";
}
/* \doc |flg_register| is used to set up an asociated between a |flag| and
a |name|. After this association is made, calls to |flg_set| can use
|name| to set the global flag. */
void flg_register( flg_Type flag, const char *name )
{
flg_Type tmp;
for (tmp = flag & 0x3fffffff; tmp && !(tmp & 1); tmp >>= 1);
if (!tmp || tmp >> 1)
err_fatal( __FUNCTION__,
"Malformed flag (%lx):"
" a single low-order bit must be set\n",
flag );
if (!hash) hash = hsh_create( NULL, NULL );
if (_flg_exists( flag ))
err_fatal( __FUNCTION__,
"The flag %lx has been used for \"%s\""
" and cannot be reused for \"%s\"\n",
flag,
flg_name( flag ),
name );
hsh_insert( hash, name, (void *)flag );
}
/* \doc |flg_set| sets the |name| flag. If |name| is ``none,'' then all
flags are cleared. */
void flg_set( const char *name )
{
flg_Type flag;
if (!name) err_internal( __FUNCTION__, "name is NULL\n" );
if (!hash) err_fatal( __FUNCTION__, "No flag names registered\n" );
if (!strcmp( name, "none" )) {
setFlags[0] = setFlags[1] = setFlags[2] = setFlags[3] = 0;
return;
}
if (!strcmp( name, "all" )) {
setFlags[0] = setFlags[1] = setFlags[2] = setFlags[3] = ~0;
return;
}
if (!(flag = (flg_Type)hsh_retrieve( hash, name ))) {
if (!(flag = (flg_Type)hsh_retrieve( hash, name+1 ))
&& *name != '-'
&& *name != '+') {
fprintf( stderr, "Valid flags are:\n" );
flg_list( stderr );
err_fatal( __FUNCTION__,
"\"%s\" is not a valid flag\n",
name );
} else {
if (*name == '+') setFlags[ flag >> 30 ] |= flag;
else setFlags[ flag >> 30 ] &= ~flag; /* - */
}
} else {
setFlags[ flag >> 30 ] |= flag;
}
}
/* \doc This inlined function tests the |flag|, returning non-zero if the
|flag| is set, and zero otherwise. */
__inline__ int flg_test( flg_Type flag )
{
return TEST( flag, setFlags );
}
/* \doc |flg_destroy| destroys the memory associated with the flag support
routines. This routine should \emph{never} be called by the programmer:
it is automatically called at program termination on systems that
support the |atexit| or |on_exit| calls. */
void flg_destroy( void )
{
if (hash) hsh_destroy( hash );
hash = NULL;
setFlags[0] = setFlags[1] = setFlags[2] = setFlags[3] = 0;
usedFlags[0] = usedFlags[1] = usedFlags[2] = usedFlags[3] = 0;
}
static int _flg_user( const void *key, const void *datum, void *arg )
{
FILE *stream = (FILE *)arg;
fprintf( stream, " %s\n", (char *)key );
return 0;
}
/* |flg_list| lists all of the valid flags to the specified |stream|. */
void flg_list( FILE *stream )
{
hsh_iterate_arg( hash, _flg_user, stream );
}
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