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 <libintl.h>
35 #include <stdbool.h>
36 #include <stdint.h>
37 #include <stdlib.h>
38 #include <errno.h>
39 
40 #include "libdwflP.h"
41 
42 
43 /* The error number.  */
44 static __thread int global_error;
45 
46 
47 int
dwfl_errno(void)48 dwfl_errno (void)
49 {
50   int result = global_error;
51   global_error = DWFL_E_NOERROR;
52   return result;
53 }
54 INTDEF (dwfl_errno)
55 
56 
57 struct msgtable
58 {
59 #define DWFL_ERROR(name, text) char msg_##name[sizeof text];
60   DWFL_ERRORS
61 #undef	DWFL_ERROR
62 };
63 
64 static const union
65 {
66   struct msgtable table;
67   char strings[
68 #define DWFL_ERROR(name, text)	+ sizeof text
69 	       DWFL_ERRORS
70 #undef	DWFL_ERROR
71 	       ];
72 } msgtable =
73   {
74     .table =
75     {
76 #define DWFL_ERROR(name, text) text,
77       DWFL_ERRORS
78 #undef	DWFL_ERROR
79     }
80   };
81 #define msgstr (msgtable.strings)
82 
83 static const uint_fast16_t msgidx[] =
84 {
85 #define DWFL_ERROR(name, text) \
86   [DWFL_E_##name] = offsetof (struct msgtable, msg_##name),
87   DWFL_ERRORS
88 #undef	DWFL_ERROR
89 };
90 #define nmsgidx (sizeof msgidx / sizeof msgidx[0])
91 
92 
93 static inline int
canonicalize(Dwfl_Error error)94 canonicalize (Dwfl_Error error)
95 {
96   unsigned int value;
97 
98   switch (error)
99     {
100     default:
101       value = error;
102       if ((value &~ 0xffff) != 0)
103 	break;
104       assert (value < nmsgidx);
105       break;
106     case DWFL_E_ERRNO:
107       value = DWFL_E (ERRNO, errno);
108       break;
109     case DWFL_E_LIBELF:
110       value = DWFL_E (LIBELF, elf_errno ());
111       break;
112     case DWFL_E_LIBDW:
113       value = DWFL_E (LIBDW, INTUSE(dwarf_errno) ());
114       break;
115 #if 0
116     DWFL_E_LIBEBL:
117       value = DWFL_E (LIBEBL, ebl_errno ());
118       break;
119 #endif
120     }
121 
122   return value;
123 }
124 
125 int
126 internal_function
__libdwfl_canon_error(Dwfl_Error error)127 __libdwfl_canon_error (Dwfl_Error error)
128 {
129   return canonicalize (error);
130 }
131 
132 void
133 internal_function
__libdwfl_seterrno(Dwfl_Error error)134 __libdwfl_seterrno (Dwfl_Error error)
135 {
136   global_error = canonicalize (error);
137 }
138 
139 
140 const char *
dwfl_errmsg(int error)141 dwfl_errmsg (int error)
142 {
143   if (error == 0 || error == -1)
144     {
145       int last_error = global_error;
146 
147       if (error == 0 && last_error == 0)
148 	return NULL;
149 
150       error = last_error;
151       global_error = DWFL_E_NOERROR;
152     }
153 
154   switch (error &~ 0xffff)
155     {
156     case OTHER_ERROR (ERRNO):
157       return strerror_r (error & 0xffff, "bad", 0);
158     case OTHER_ERROR (LIBELF):
159       return elf_errmsg (error & 0xffff);
160     case OTHER_ERROR (LIBDW):
161       return INTUSE(dwarf_errmsg) (error & 0xffff);
162 #if 0
163     case OTHER_ERROR (LIBEBL):
164       return ebl_errmsg (error & 0xffff);
165 #endif
166     }
167 
168   return _(&msgstr[msgidx[(unsigned int) error < nmsgidx
169 			  ? error : DWFL_E_UNKNOWN_ERROR]]);
170 }
171 INTDEF (dwfl_errmsg)
172