1 /* Find entry breakpoint locations for a function.
2 Copyright (C) 2005, 2008 Red Hat, Inc.
3 This file is part of Red Hat elfutils.
4
5 Red Hat elfutils is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by the
7 Free Software Foundation; version 2 of the License.
8
9 Red Hat elfutils is distributed in the hope that it will be useful, but
10 WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 General Public License for more details.
13
14 You should have received a copy of the GNU General Public License along
15 with Red Hat elfutils; if not, write to the Free Software Foundation,
16 Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
17
18 In addition, as a special exception, Red Hat, Inc. gives You the
19 additional right to link the code of Red Hat elfutils with code licensed
20 under any Open Source Initiative certified open source license
21 (http://www.opensource.org/licenses/index.php) which requires the
22 distribution of source code with any binary distribution and to
23 distribute linked combinations of the two. Non-GPL Code permitted under
24 this exception must only link to the code of Red Hat elfutils through
25 those well defined interfaces identified in the file named EXCEPTION
26 found in the source code files (the "Approved Interfaces"). The files
27 of Non-GPL Code may instantiate templates or use macros or inline
28 functions from the Approved Interfaces without causing the resulting
29 work to be covered by the GNU General Public License. Only Red Hat,
30 Inc. may make changes or additions to the list of Approved Interfaces.
31 Red Hat's grant of this exception is conditioned upon your not adding
32 any new exceptions. If you wish to add a new Approved Interface or
33 exception, please contact Red Hat. You must obey the GNU General Public
34 License in all respects for all of the Red Hat elfutils code and other
35 code used in conjunction with Red Hat elfutils except the Non-GPL Code
36 covered by this exception. If you modify this file, you may extend this
37 exception to your version of the file, but you are not obligated to do
38 so. If you do not wish to provide this exception without modification,
39 you must delete this exception statement from your version and license
40 this file solely under the GPL without exception.
41
42 Red Hat elfutils is an included package of the Open Invention Network.
43 An included package of the Open Invention Network is a package for which
44 Open Invention Network licensees cross-license their patents. No patent
45 license is granted, either expressly or impliedly, by designation as an
46 included package. Should you wish to participate in the Open Invention
47 Network licensing program, please visit www.openinventionnetwork.com
48 <http://www.openinventionnetwork.com>. */
49
50 #ifdef HAVE_CONFIG_H
51 # include <config.h>
52 #endif
53 #include "libdwP.h"
54 #include <dwarf.h>
55 #include <stdlib.h>
56
57
58 int
dwarf_entry_breakpoints(die,bkpts)59 dwarf_entry_breakpoints (die, bkpts)
60 Dwarf_Die *die;
61 Dwarf_Addr **bkpts;
62 {
63 int nbkpts = 0;
64 *bkpts = NULL;
65
66 /* Add one breakpoint location to the result vector. */
67 inline int add_bkpt (Dwarf_Addr pc)
68 {
69 Dwarf_Addr *newlist = realloc (*bkpts, ++nbkpts * sizeof newlist[0]);
70 if (newlist == NULL)
71 {
72 free (*bkpts);
73 *bkpts = NULL;
74 __libdw_seterrno (DWARF_E_NOMEM);
75 return -1;
76 }
77 newlist[nbkpts - 1] = pc;
78 *bkpts = newlist;
79 return nbkpts;
80 }
81
82 /* Fallback result, break at the entrypc/lowpc value. */
83 inline int entrypc_bkpt (void)
84 {
85 Dwarf_Addr pc;
86 return INTUSE(dwarf_entrypc) (die, &pc) < 0 ? -1 : add_bkpt (pc);
87 }
88
89 /* Fetch the CU's line records to look for this DIE's addresses. */
90 Dwarf_Die cudie = CUDIE (die->cu);
91 Dwarf_Lines *lines;
92 size_t nlines;
93 if (INTUSE(dwarf_getsrclines) (&cudie, &lines, &nlines) < 0)
94 {
95 int error = INTUSE (dwarf_errno) ();
96 if (error == DWARF_E_NO_DEBUG_LINE)
97 return entrypc_bkpt ();
98 __libdw_seterrno (error);
99 return -1;
100 }
101
102 /* Search a contiguous PC range for prologue-end markers.
103 If DWARF, look for proper markers.
104 Failing that, if ADHOC, look for the ad hoc convention. */
105 inline int search_range (Dwarf_Addr low, Dwarf_Addr high,
106 bool dwarf, bool adhoc)
107 {
108 size_t l = 0, u = nlines;
109 while (l < u)
110 {
111 size_t idx = (l + u) / 2;
112 if (lines->info[idx].addr < low)
113 l = idx + 1;
114 else if (lines->info[idx].addr > low)
115 u = idx;
116 else if (lines->info[idx].end_sequence)
117 l = idx + 1;
118 else
119 {
120 l = idx;
121 break;
122 }
123 }
124 if (l < u)
125 {
126 if (dwarf)
127 for (size_t i = l; i < u && lines->info[i].addr < high; ++i)
128 if (lines->info[i].prologue_end
129 && add_bkpt (lines->info[i].addr) < 0)
130 return -1;
131 if (adhoc && nbkpts == 0)
132 while (++l < nlines && lines->info[l].addr < high)
133 if (!lines->info[l].end_sequence)
134 return add_bkpt (lines->info[l].addr);
135 return nbkpts;
136 }
137 __libdw_seterrno (DWARF_E_INVALID_DWARF);
138 return -1;
139 }
140
141 /* Search each contiguous address range for DWARF prologue_end markers. */
142
143 Dwarf_Addr base;
144 Dwarf_Addr begin;
145 Dwarf_Addr end;
146 ptrdiff_t offset = INTUSE(dwarf_ranges) (die, 0, &base, &begin, &end);
147 if (offset < 0)
148 return -1;
149
150 /* Most often there is a single contiguous PC range for the DIE. */
151 if (offset == 1)
152 return search_range (begin, end, true, true) ?: entrypc_bkpt ();
153
154 Dwarf_Addr lowpc = (Dwarf_Addr) -1l;
155 Dwarf_Addr highpc = (Dwarf_Addr) -1l;
156 while (offset > 0)
157 {
158 /* We have an address range entry. */
159 if (search_range (begin, end, true, false) < 0)
160 return -1;
161
162 if (begin < lowpc)
163 {
164 lowpc = begin;
165 highpc = end;
166 }
167
168 offset = INTUSE(dwarf_ranges) (die, offset, &base, &begin, &end);
169 }
170
171 /* If we didn't find any proper DWARF markers, then look in the
172 lowest-addressed range for an ad hoc marker. Failing that,
173 fall back to just using the entrypc value. */
174 return (nbkpts
175 ?: (lowpc == (Dwarf_Addr) -1l ? 0
176 : search_range (lowpc, highpc, false, true))
177 ?: entrypc_bkpt ());
178 }
179