IABSD.fr/src/include/bitstring.h

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• Author : bluhm
  Date : 2024-08-26 11:52:54
  Hash : 4491bd90
  Message : Evaluate arguments of bitstring macros only once. According to bit_alloc(3) man page the arguments to bitstring macros are evaluated only once and may safely have side effects. Fix the implementation with temporary variables to fulfill this requirement. OK florian@ deraadt@

• include/bitstring.h

• /*	$OpenBSD: bitstring.h,v 1.7 2024/08/26 11:52:54 bluhm Exp $	*/
  /*	$NetBSD: bitstring.h,v 1.5 1997/05/14 15:49:55 pk Exp $	*/
  
  /*
   * Copyright (c) 1989, 1993
   *	The Regents of the University of California.  All rights reserved.
   *
   * This code is derived from software contributed to Berkeley by
   * Paul Vixie.
   *
   * 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. 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.
   *
   *	@(#)bitstring.h	8.1 (Berkeley) 7/19/93
   */
  
  #ifndef _BITSTRING_H_
  #define	_BITSTRING_H_
  
  /* modified for SV/AT and bitstring bugfix by M.R.Murphy, 11oct91
   * bitstr_size changed gratuitously, but shorter
   * bit_alloc   spelling error fixed
   * the following were efficient, but didn't work, they've been made to
   * work, but are no longer as efficient :-)
   * bit_nclear, bit_nset, bit_ffc, bit_ffs
   */
  typedef	unsigned char bitstr_t;
  
  /* internal macros */
  				/* byte of the bitstring bit is in */
  #define	_bit_byte(bit) \
  	((bit) >> 3)
  
  				/* mask for the bit within its byte */
  #define	_bit_mask(bit) \
  	(1 << ((bit)&0x7))
  
  /* external macros */
  				/* bytes in a bitstring of nbits bits */
  #define	bitstr_size(nbits) \
  	(((nbits) + 7) >> 3)
  
  				/* allocate a bitstring */
  #define	bit_alloc(nbits) \
  	(bitstr_t *)calloc((size_t)bitstr_size(nbits), sizeof(bitstr_t))
  
  				/* allocate a bitstring on the stack */
  #define	bit_decl(name, nbits) \
  	((name)[bitstr_size(nbits)])
  
  				/* is bit N of bitstring name set? */
  #define	bit_test(name, bit) ({ \
  	register int __tbit = (bit); \
  	((name)[_bit_byte(__tbit)] & _bit_mask(__tbit)); \
  })
  
  				/* set bit N of bitstring name */
  #define	bit_set(name, bit) do { \
  	register int __sbit = (bit); \
  	((name)[_bit_byte(__sbit)] |= _bit_mask(__sbit)); \
  } while(0)
  
  				/* clear bit N of bitstring name */
  #define	bit_clear(name, bit) do { \
  	register int __cbit = (bit); \
  	((name)[_bit_byte(__cbit)] &= ~_bit_mask(__cbit)); \
  } while(0)
  
  				/* clear bits start ... stop in bitstring */
  #define	bit_nclear(name, start, stop) do { \
  	register bitstr_t *__name = (name); \
  	register int __start = (start), __stop = (stop); \
  	while (__start <= __stop) { \
  		bit_clear(__name, __start); \
  		__start++; \
  		} \
  } while(0)
  
  				/* set bits start ... stop in bitstring */
  #define	bit_nset(name, start, stop) do { \
  	register bitstr_t *__name = (name); \
  	register int __start = (start), __stop = (stop); \
  	while (__start <= __stop) { \
  		bit_set(__name, __start); \
  		__start++; \
  		} \
  } while(0)
  
  				/* find first bit clear in name */
  #define	bit_ffc(name, nbits, value) do { \
  	register bitstr_t *__name = (name); \
  	register int __bit, __nbits = (nbits), __value = -1; \
  	for (__bit = 0; __bit < __nbits; ++__bit) \
  		if (!bit_test(__name, __bit)) { \
  			__value = __bit; \
  			break; \
  		} \
  	*(value) = __value; \
  } while(0)
  
  				/* find first bit set in name */
  #define	bit_ffs(name, nbits, value) do { \
  	register bitstr_t *__name = (name); \
  	register int __bit, __nbits = (nbits), __value = -1; \
  	for (__bit = 0; __bit < __nbits; ++__bit) \
  		if (bit_test(__name, __bit)) { \
  			__value = __bit; \
  			break; \
  		} \
  	*(value) = __value; \
  } while(0)
  
  #endif /* !_BITSTRING_H_ */