1  /* A simple, memory-efficient bitset implementation.
       2  
       3     Copyright (C) 2009-2015, 2018-2021 Free Software Foundation, Inc.
       4  
       5     This file is part of Bison, the GNU Compiler Compiler.
       6  
       7     This program is free software: you can redistribute it and/or modify
       8     it under the terms of the GNU General Public License as published by
       9     the Free Software Foundation, either version 3 of the License, or
      10     (at your option) any later version.
      11  
      12     This program is distributed in the hope that it will be useful,
      13     but WITHOUT ANY WARRANTY; without even the implied warranty of
      14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      15     GNU General Public License for more details.
      16  
      17     You should have received a copy of the GNU General Public License
      18     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
      19  
      20  #include <config.h>
      21  #include "system.h"
      22  
      23  #include "Sbitset.h"
      24  
      25  Sbitset
      26  Sbitset__new (Sbitset__Index nbits)
      27  {
      28    /* Some functions, like Sbitset__last_byte_mask, will fail if nbits = 0.  */
      29    aver (nbits);
      30    return xcalloc (1, Sbitset__nbytes (nbits));
      31  }
      32  
      33  Sbitset
      34  Sbitset__new_on_obstack (Sbitset__Index nbits, struct obstack *obstackp)
      35  {
      36    Sbitset result;
      37    Sbitset ptr;
      38    Sbitset end;
      39    aver (nbits);
      40    result = obstack_alloc (obstackp, Sbitset__nbytes (nbits));
      41    for (ptr = result, end = result + Sbitset__nbytes (nbits); ptr < end; ++ptr)
      42      *ptr = 0;
      43    return result;
      44  }
      45  
      46  void
      47  Sbitset__delete (Sbitset self)
      48  {
      49    free (self);
      50  }
      51  
      52  bool
      53  Sbitset__isEmpty (Sbitset self, Sbitset__Index nbits)
      54  {
      55    Sbitset last = self + Sbitset__nbytes (nbits) - 1;
      56    for (; self < last; ++self)
      57      if (*self != 0)
      58        return false;
      59    return ((*last) & Sbitset__last_byte_mask (nbits)) == 0;
      60  }
      61  
      62  void
      63  Sbitset__fprint (Sbitset self, Sbitset__Index nbits, FILE *file)
      64  {
      65    Sbitset__Index i;
      66    Sbitset itr;
      67    bool first = true;
      68    fprintf (file,
      69             "nbits = %" SBITSET__INDEX__CONVERSION_SPEC ", set = {",
      70             nbits);
      71    SBITSET__FOR_EACH (self, nbits, itr, i)
      72      {
      73        if (first)
      74          first = false;
      75        else
      76          fprintf (file, ",");
      77        fprintf (file, " %" SBITSET__INDEX__CONVERSION_SPEC, i);
      78      }
      79    fprintf (file, " }");
      80  }