xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/memrange.c (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f)
1 /* Memory ranges
2 
3    Copyright (C) 2010-2017 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 #include <algorithm>
23 
24 int
25 mem_ranges_overlap (CORE_ADDR start1, int len1,
26 		    CORE_ADDR start2, int len2)
27 {
28   ULONGEST h, l;
29 
30   l = std::max (start1, start2);
31   h = std::min (start1 + len1, start2 + len2);
32   return (l < h);
33 }
34 
35 /* See memrange.h.  */
36 
37 int
38 address_in_mem_range (CORE_ADDR address, const struct mem_range *r)
39 {
40   return (r->start <= address
41 	  && (address - r->start) < r->length);
42 }
43 
44 /* qsort comparison function, that compares mem_ranges.  Ranges are
45    sorted in ascending START order.  */
46 
47 static int
48 compare_mem_ranges (const void *ap, const void *bp)
49 {
50   const struct mem_range *r1 = (const struct mem_range *) ap;
51   const struct mem_range *r2 = (const struct mem_range *) bp;
52 
53   if (r1->start > r2->start)
54     return 1;
55   else if (r1->start < r2->start)
56     return -1;
57   else
58     return 0;
59 }
60 
61 void
62 normalize_mem_ranges (VEC(mem_range_s) *ranges)
63 {
64   /* This function must not use any VEC operation on RANGES that
65      reallocates the memory block as that invalidates the RANGES
66      pointer, which callers expect to remain valid.  */
67 
68   if (!VEC_empty (mem_range_s, ranges))
69     {
70       struct mem_range *ra, *rb;
71       int a, b;
72 
73       qsort (VEC_address (mem_range_s, ranges),
74 	     VEC_length (mem_range_s, ranges),
75 	     sizeof (mem_range_s),
76 	     compare_mem_ranges);
77 
78       a = 0;
79       ra = VEC_index (mem_range_s, ranges, a);
80       for (b = 1; VEC_iterate (mem_range_s, ranges, b, rb); b++)
81 	{
82 	  /* If mem_range B overlaps or is adjacent to mem_range A,
83 	     merge them.  */
84 	  if (rb->start <= ra->start + ra->length)
85 	    {
86 	      ra->length = std::max ((CORE_ADDR) ra->length,
87 				(rb->start - ra->start) + rb->length);
88 	      continue;		/* next b, same a */
89 	    }
90 	  a++;			/* next a */
91 	  ra = VEC_index (mem_range_s, ranges, a);
92 
93 	  if (a != b)
94 	    *ra = *rb;
95 	}
96       VEC_truncate (mem_range_s, ranges, a + 1);
97     }
98 }
99