xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/memrange.c (revision e5cb852c65c532c79a7d83e6e6c8663886e00327)
1 /* Memory ranges
2 
3    Copyright (C) 2010-2016 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 /* See memrange.h.  */
35 
36 int
37 address_in_mem_range (CORE_ADDR address, const struct mem_range *r)
38 {
39   return (r->start <= address
40 	  && (address - r->start) < r->length);
41 }
42 
43 /* qsort comparison function, that compares mem_ranges.  Ranges are
44    sorted in ascending START order.  */
45 
46 static int
47 compare_mem_ranges (const void *ap, const void *bp)
48 {
49   const struct mem_range *r1 = (const struct mem_range *) ap;
50   const struct mem_range *r2 = (const struct mem_range *) bp;
51 
52   if (r1->start > r2->start)
53     return 1;
54   else if (r1->start < r2->start)
55     return -1;
56   else
57     return 0;
58 }
59 
60 void
61 normalize_mem_ranges (VEC(mem_range_s) *ranges)
62 {
63   /* This function must not use any VEC operation on RANGES that
64      reallocates the memory block as that invalidates the RANGES
65      pointer, which callers expect to remain valid.  */
66 
67   if (!VEC_empty (mem_range_s, ranges))
68     {
69       struct mem_range *ra, *rb;
70       int a, b;
71 
72       qsort (VEC_address (mem_range_s, ranges),
73 	     VEC_length (mem_range_s, ranges),
74 	     sizeof (mem_range_s),
75 	     compare_mem_ranges);
76 
77       a = 0;
78       ra = VEC_index (mem_range_s, ranges, a);
79       for (b = 1; VEC_iterate (mem_range_s, ranges, b, rb); b++)
80 	{
81 	  /* If mem_range B overlaps or is adjacent to mem_range A,
82 	     merge them.  */
83 	  if (rb->start <= ra->start + ra->length)
84 	    {
85 	      ra->length = max (ra->length,
86 				(rb->start - ra->start) + rb->length);
87 	      continue;		/* next b, same a */
88 	    }
89 	  a++;			/* next a */
90 	  ra = VEC_index (mem_range_s, ranges, a);
91 
92 	  if (a != b)
93 	    *ra = *rb;
94 	}
95       VEC_truncate (mem_range_s, ranges, a + 1);
96     }
97 }
98