1  /*
       2   * Copyright (c) 2016-2018 Dmitry V. Levin <ldv@strace.io>
       3   * Copyright (c) 2017-2021 The strace developers.
       4   * All rights reserved.
       5   *
       6   * SPDX-License-Identifier: LGPL-2.1-or-later
       7   */
       8  
       9  #ifdef HAVE_CONFIG_H
      10  # include "config.h"
      11  #endif
      12  
      13  #include <stdbool.h>
      14  #include <stdlib.h>
      15  #include <string.h>
      16  #include "defs.h"
      17  #include "number_set.h"
      18  #include "static_assert.h"
      19  #include "xmalloc.h"
      20  
      21  typedef unsigned int number_slot_t;
      22  #define BITS_PER_SLOT (sizeof(number_slot_t) * 8)
      23  
      24  struct number_set {
      25  	number_slot_t *vec;
      26  	unsigned int nslots;
      27  	bool not;
      28  };
      29  
      30  static void
      31  number_setbit(const unsigned int i, number_slot_t *const vec)
      32  {
      33  	vec[i / BITS_PER_SLOT] |= (number_slot_t) 1 << (i % BITS_PER_SLOT);
      34  }
      35  
      36  static bool
      37  number_isset(const unsigned int i, const number_slot_t *const vec)
      38  {
      39  	return vec[i / BITS_PER_SLOT] & ((number_slot_t) 1 << (i % BITS_PER_SLOT));
      40  }
      41  
      42  static void
      43  reallocate_number_set(struct number_set *const set, const unsigned int new_nslots)
      44  {
      45  	if (new_nslots <= set->nslots)
      46  		return;
      47  	set->vec = xreallocarray(set->vec, new_nslots, sizeof(*set->vec));
      48  	memset(set->vec + set->nslots, 0,
      49  	       sizeof(*set->vec) * (new_nslots - set->nslots));
      50  	set->nslots = new_nslots;
      51  }
      52  
      53  static unsigned int
      54  get_number_setbit(const struct number_set *const set)
      55  {
      56  	static_assert(sizeof(number_slot_t) == sizeof(uint32_t),
      57  		      "number_slot_t is not 32-bit long");
      58  	return popcount32(set->vec, set->nslots);
      59  }
      60  
      61  bool
      62  number_set_array_is_empty(const struct number_set *const set,
      63  			  const unsigned int idx)
      64  {
      65  	return !(set && (set[idx].nslots || set[idx].not));
      66  }
      67  
      68  bool
      69  is_number_in_set(const unsigned int number, const struct number_set *const set)
      70  {
      71  	return set && ((number / BITS_PER_SLOT < set->nslots)
      72  		&& number_isset(number, set->vec)) ^ set->not;
      73  }
      74  
      75  bool
      76  is_number_in_set_array(const unsigned int number, const struct number_set *const set,
      77  		       const unsigned int idx)
      78  {
      79  	return set && ((number / BITS_PER_SLOT < set[idx].nslots)
      80  		&& number_isset(number, set[idx].vec)) ^ set[idx].not;
      81  }
      82  
      83  bool
      84  is_complete_set(const struct number_set *const set, const unsigned int max_numbers)
      85  {
      86  	return set && ((set->not && !set->nslots) ||
      87  		       (get_number_setbit(set) == max_numbers));
      88  }
      89  
      90  bool
      91  is_complete_set_array(const struct number_set *const set,
      92  		      const unsigned int *const max_numbers,
      93  		      const unsigned int nmemb)
      94  {
      95  	for (unsigned int i = 0; i < nmemb; ++i) {
      96  		if (!is_complete_set(&set[i], max_numbers[i]))
      97  			return false;
      98  	}
      99  	return true;
     100  }
     101  
     102  void
     103  add_number_to_set(const unsigned int number, struct number_set *const set)
     104  {
     105  	reallocate_number_set(set, number / BITS_PER_SLOT + 1);
     106  	number_setbit(number, set->vec);
     107  }
     108  
     109  void
     110  add_number_to_set_array(const unsigned int number, struct number_set *const set,
     111  			const unsigned int idx)
     112  {
     113  	add_number_to_set(number, &set[idx]);
     114  }
     115  
     116  void
     117  clear_number_set_array(struct number_set *const set, const unsigned int nmemb)
     118  {
     119  	for (unsigned int i = 0; i < nmemb; ++i) {
     120  		if (set[i].nslots)
     121  			memset(set[i].vec, 0,
     122  			       sizeof(*set[i].vec) * set[i].nslots);
     123  		set[i].not = false;
     124  	}
     125  }
     126  
     127  void
     128  invert_number_set_array(struct number_set *const set, const unsigned int nmemb)
     129  {
     130  	for (unsigned int i = 0; i < nmemb; ++i)
     131  		set[i].not = !set[i].not;
     132  }
     133  
     134  struct number_set *
     135  alloc_number_set_array(const unsigned int nmemb)
     136  {
     137  	return xcalloc(nmemb, sizeof(struct number_set));
     138  }
     139  
     140  void
     141  free_number_set_array(struct number_set *const set, unsigned int nmemb)
     142  {
     143  	while (nmemb) {
     144  		--nmemb;
     145  		free(set[nmemb].vec);
     146  		set[nmemb].vec = NULL;
     147  	}
     148  	free(set);
     149  }