1 /* Error handling in libdwfl.
2 Copyright (C) 2005-2015 Red Hat, Inc.
3 This file is part of elfutils.
4
5 This file is free software; you can redistribute it and/or modify
6 it under the terms of either
7
8 * the GNU Lesser General Public License as published by the Free
9 Software Foundation; either version 3 of the License, or (at
10 your option) any later version
11
12 or
13
14 * the GNU General Public License as published by the Free
15 Software Foundation; either version 2 of the License, or (at
16 your option) any later version
17
18 or both in parallel, as here.
19
20 elfutils is distributed in the hope that it will be useful, but
21 WITHOUT ANY WARRANTY; without even the implied warranty of
22 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23 General Public License for more details.
24
25 You should have received copies of the GNU General Public License and
26 the GNU Lesser General Public License along with this program. If
27 not, see <http://www.gnu.org/licenses/>. */
28
29 #ifdef HAVE_CONFIG_H
30 # include <config.h>
31 #endif
32
33 #include <assert.h>
34 #include <stdbool.h>
35 #include <stdint.h>
36 #include <stdlib.h>
37 #include <errno.h>
38
39 #include "libdwflP.h"
40
41
42 /* The error number. */
43 static __thread int global_error;
44
45
46 int
dwfl_errno(void)47 dwfl_errno (void)
48 {
49 int result = global_error;
50 global_error = DWFL_E_NOERROR;
51 return result;
52 }
53 INTDEF (dwfl_errno)
54
55
56 struct msgtable
57 {
58 #define DWFL_ERROR(name, text) char msg_##name[sizeof text];
59 DWFL_ERRORS
60 #undef DWFL_ERROR
61 };
62
63 static const union
64 {
65 struct msgtable table;
66 char strings[
67 #define DWFL_ERROR(name, text) + sizeof text
68 DWFL_ERRORS
69 #undef DWFL_ERROR
70 ];
71 } msgtable =
72 {
73 .table =
74 {
75 #define DWFL_ERROR(name, text) text,
76 DWFL_ERRORS
77 #undef DWFL_ERROR
78 }
79 };
80 #define msgstr (msgtable.strings)
81
82 static const uint_fast16_t msgidx[] =
83 {
84 #define DWFL_ERROR(name, text) \
85 [DWFL_E_##name] = offsetof (struct msgtable, msg_##name),
86 DWFL_ERRORS
87 #undef DWFL_ERROR
88 };
89 #define nmsgidx (sizeof msgidx / sizeof msgidx[0])
90
91
92 static inline int
canonicalize(Dwfl_Error error)93 canonicalize (Dwfl_Error error)
94 {
95 unsigned int value;
96
97 switch (error)
98 {
99 default:
100 value = error;
101 if ((value &~ 0xffff) != 0)
102 break;
103 assert (value < nmsgidx);
104 break;
105 case DWFL_E_ERRNO:
106 value = DWFL_E (ERRNO, errno);
107 break;
108 case DWFL_E_LIBELF:
109 value = DWFL_E (LIBELF, elf_errno ());
110 break;
111 case DWFL_E_LIBDW:
112 value = DWFL_E (LIBDW, INTUSE(dwarf_errno) ());
113 break;
114 #if 0
115 DWFL_E_LIBEBL:
116 value = DWFL_E (LIBEBL, ebl_errno ());
117 break;
118 #endif
119 }
120
121 return value;
122 }
123
124 int
125 internal_function
__libdwfl_canon_error(Dwfl_Error error)126 __libdwfl_canon_error (Dwfl_Error error)
127 {
128 return canonicalize (error);
129 }
130
131 void
132 internal_function
__libdwfl_seterrno(Dwfl_Error error)133 __libdwfl_seterrno (Dwfl_Error error)
134 {
135 global_error = canonicalize (error);
136 }
137
138
139 static const char *
errnomsg(int error)140 errnomsg(int error)
141 {
142 /* Won't be changed by strerror_r, but not const so compiler doesn't throw warning */
143 static char unknown[] = "unknown error";
144
145 #ifdef STRERROR_R_CHAR_P
146 return strerror_r (error, unknown, 0);
147 #else
148 /* To store the error message from strerror_r in a thread-safe manner */
149 static __thread char msg[128];
150 return strerror_r (error, msg, sizeof (msg)) ? unknown : msg;
151 #endif
152 }
153
154 const char *
dwfl_errmsg(int error)155 dwfl_errmsg (int error)
156 {
157 if (error == 0 || error == -1)
158 {
159 int last_error = global_error;
160
161 if (error == 0 && last_error == 0)
162 return NULL;
163
164 error = last_error;
165 global_error = DWFL_E_NOERROR;
166 }
167
168 switch (error &~ 0xffff)
169 {
170 case OTHER_ERROR (ERRNO):
171 return errnomsg (error & 0xffff);
172 case OTHER_ERROR (LIBELF):
173 return elf_errmsg (error & 0xffff);
174 case OTHER_ERROR (LIBDW):
175 return INTUSE(dwarf_errmsg) (error & 0xffff);
176 #if 0
177 case OTHER_ERROR (LIBEBL):
178 return ebl_errmsg (error & 0xffff);
179 #endif
180 }
181
182 return _(&msgstr[msgidx[(unsigned int) error < nmsgidx
183 ? error : DWFL_E_UNKNOWN_ERROR]]);
184 }
185 INTDEF (dwfl_errmsg)
186