gdb/memrange.c

   1 /* Memory ranges
   2
   3    Copyright (C) 2010-2014 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   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 <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "memrange.h"
  22
  23 int
  24 mem_ranges_overlap (CORE_ADDR start1, int len1,
  25                     CORE_ADDR start2, int len2)
  26 {
  27   ULONGEST h, l;
  28
  29   l = max (start1, start2);
  30   h = min (start1 + len1, start2 + len2);
  31   return (l < h);
  32 }
  33
  34 /* qsort comparison function, that compares mem_ranges.  Ranges are
  35    sorted in ascending START order.  */
  36
  37 static int
  38 compare_mem_ranges (const void *ap, const void *bp)
  39 {
  40   const struct mem_range *r1 = ap;
  41   const struct mem_range *r2 = bp;
  42
  43   if (r1->start > r2->start)
  44     return 1;
  45   else if (r1->start < r2->start)
  46     return -1;
  47   else
  48     return 0;
  49 }
  50
  51 void
  52 normalize_mem_ranges (VEC(mem_range_s) *ranges)
  53 {
  54   /* This function must not use any VEC operation on RANGES that
  55      reallocates the memory block as that invalidates the RANGES
  56      pointer, which callers expect to remain valid.  */
  57
  58   if (!VEC_empty (mem_range_s, ranges))
  59     {
  60       struct mem_range *ra, *rb;
  61       int a, b;
  62
  63       qsort (VEC_address (mem_range_s, ranges),
  64              VEC_length (mem_range_s, ranges),
  65              sizeof (mem_range_s),
  66              compare_mem_ranges);
  67
  68       a = 0;
  69       ra = VEC_index (mem_range_s, ranges, a);
  70       for (b = 1; VEC_iterate (mem_range_s, ranges, b, rb); b++)
  71         {
  72           /* If mem_range B overlaps or is adjacent to mem_range A,
  73              merge them.  */
  74           if (rb->start <= ra->start + ra->length)
  75             {
  76               ra->length = max (ra->length,
  77                                 (rb->start - ra->start) + rb->length);
  78               continue;         /* next b, same a */
  79             }
  80           a++;                  /* next a */
  81           ra = VEC_index (mem_range_s, ranges, a);
  82
  83           if (a != b)
  84             *ra = *rb;
  85         }
  86       VEC_truncate (mem_range_s, ranges, a + 1);
  87     }
  88 }