gcc/varray.c

   1 /* Virtual array support.
   2    Copyright (C) 1998 Free Software Foundation, Inc.
   3    Contributed by Cygnus Solutions.
   4
   5    This file is part of GNU CC.
   6
   7    GNU CC is free software; you can redistribute it and/or modify it
   8    under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2, or (at your option)
  10    any later version.
  11
  12    GNU CC is distributed in the hope that it will be useful, but
  13    WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15    General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with GNU CC; see the file COPYING.  If not, write to the Free
  19    the Free Software Foundation, 59 Temple Place - Suite 330,
  20    Boston, MA 02111-1307, USA.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "rtl.h"
  25 #include "tree.h"
  26 #include "bitmap.h"
  27 #include "varray.h"
  28
  29 #define VARRAY_HDR_SIZE (sizeof (struct varray_head_tag) - sizeof (varray_data))
  30
  31 /* Allocate a virtual array with NUM_ELEMENT elements, each of which is
  32    ELEMENT_SIZE bytes long, named NAME.  Array elements are zeroed.  */
  33 varray_type
  34 varray_init (num_elements, element_size, name)
  35      size_t num_elements;
  36      size_t element_size;
  37      const char *name;
  38 {
  39   size_t data_size = num_elements * element_size;
  40   varray_type ptr = (varray_type) xcalloc (VARRAY_HDR_SIZE + data_size, 1);
  41
  42   ptr->num_elements = num_elements;
  43   ptr->element_size = element_size;
  44   ptr->name         = name;
  45   return ptr;
  46 }
  47
  48 /* Grow/shrink the virtual array VA to N elements.  Zero any new elements
  49    allocated.  */
  50 varray_type
  51 varray_grow (va, n)
  52      varray_type va;
  53      size_t n;
  54 {
  55   size_t old_elements = va->num_elements;
  56
  57   if (n != old_elements)
  58     {
  59       size_t element_size = va->element_size;
  60       size_t old_data_size = old_elements * element_size;
  61       size_t data_size = n * element_size;
  62
  63       va = (varray_type) xrealloc ((char *)va, VARRAY_HDR_SIZE + data_size);
  64       va->num_elements = n;
  65       if (n > old_elements)
  66         bzero (&va->data.c[old_data_size], data_size - old_data_size);
  67     }
  68
  69   return va;
  70 }