gcc/varray.c

   1 /* Virtual array support.
   2    Copyright (C) 1998, 1999, 2000 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->elements_used = 0;
  44   ptr->element_size = element_size;
  45   ptr->name = name;
  46   return ptr;
  47 }
  48
  49 /* Grow/shrink the virtual array VA to N elements.  Zero any new elements
  50    allocated.  */
  51 varray_type
  52 varray_grow (va, n)
  53      varray_type va;
  54      size_t n;
  55 {
  56   size_t old_elements = va->num_elements;
  57
  58   if (n != old_elements)
  59     {
  60       size_t element_size = va->element_size;
  61       size_t old_data_size = old_elements * element_size;
  62       size_t data_size = n * element_size;
  63
  64       va = (varray_type) xrealloc ((char *)va, VARRAY_HDR_SIZE + data_size);
  65       va->num_elements = n;
  66       if (n > old_elements)
  67         memset (&va->data.c[old_data_size], 0, data_size - old_data_size);
  68     }
  69
  70   return va;
  71 }
  72
  73 /* Check the bounds of a varray access.  */
  74
  75 #if defined ENABLE_CHECKING && (GCC_VERSION >= 2007)
  76
  77 extern void error PARAMS ((const char *, ...))  ATTRIBUTE_PRINTF_1;
  78
  79 void
  80 varray_check_failed (va, n, file, line, function)
  81      varray_type va;
  82      size_t n;
  83      const char *file;
  84      int line;
  85      const char *function;
  86 {
  87   error("Virtual array %s[%lu]: element %lu out of bounds",
  88         va->name, (unsigned long) va->num_elements, (unsigned long) n);
  89   fancy_abort (file, line, function);
  90 }
  91
  92 #endif