xref: /dragonfly/contrib/gdb-7/gdb/memrange.c (revision 8af44722)
1 /* Memory ranges
2 
3    Copyright (C) 2010-2013 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 }
89