1 /* Error handling in libdwfl.
2    Copyright (C) 2005-2010 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 static const struct msgtable
58 {
59 #define DWFL_ERROR(name, text) char msg_##name[sizeof text];
60   DWFL_ERRORS
61 #undef	DWFL_ERROR
62 } msgtable =
63   {
64 #define DWFL_ERROR(name, text) text,
65   DWFL_ERRORS
66 #undef	DWFL_ERROR
67   };
68 #define msgstr (&msgtable.msg_NOERROR[0])
69 
70 static const uint_fast16_t msgidx[] =
71 {
72 #define DWFL_ERROR(name, text) \
73   [DWFL_E_##name] = offsetof (struct msgtable, msg_##name),
74   DWFL_ERRORS
75 #undef	DWFL_ERROR
76 };
77 #define nmsgidx (sizeof msgidx / sizeof msgidx[0])
78 
79 
80 static inline int
canonicalize(Dwfl_Error error)81 canonicalize (Dwfl_Error error)
82 {
83   unsigned int value;
84 
85   switch (error)
86     {
87     default:
88       value = error;
89       if ((value &~ 0xffff) != 0)
90 	break;
91       assert (value < nmsgidx);
92       break;
93     case DWFL_E_ERRNO:
94       value = DWFL_E (ERRNO, errno);
95       break;
96     case DWFL_E_LIBELF:
97       value = DWFL_E (LIBELF, elf_errno ());
98       break;
99     case DWFL_E_LIBDW:
100       value = DWFL_E (LIBDW, INTUSE(dwarf_errno) ());
101       break;
102 #if 0
103     DWFL_E_LIBEBL:
104       value = DWFL_E (LIBEBL, ebl_errno ());
105       break;
106 #endif
107     }
108 
109   return value;
110 }
111 
112 int
113 internal_function
__libdwfl_canon_error(Dwfl_Error error)114 __libdwfl_canon_error (Dwfl_Error error)
115 {
116   return canonicalize (error);
117 }
118 
119 void
120 internal_function
__libdwfl_seterrno(Dwfl_Error error)121 __libdwfl_seterrno (Dwfl_Error error)
122 {
123   global_error = canonicalize (error);
124 }
125 
126 
127 const char *
dwfl_errmsg(error)128 dwfl_errmsg (error)
129      int error;
130 {
131   if (error == 0 || error == -1)
132     {
133       int last_error = global_error;
134 
135       if (error == 0 && last_error == 0)
136 	return NULL;
137 
138       error = last_error;
139       global_error = DWFL_E_NOERROR;
140     }
141 
142   switch (error &~ 0xffff)
143     {
144     case OTHER_ERROR (ERRNO):
145       return strerror_r (error & 0xffff, "bad", 0);
146     case OTHER_ERROR (LIBELF):
147       return elf_errmsg (error & 0xffff);
148     case OTHER_ERROR (LIBDW):
149       return INTUSE(dwarf_errmsg) (error & 0xffff);
150 #if 0
151     case OTHER_ERROR (LIBEBL):
152       return ebl_errmsg (error & 0xffff);
153 #endif
154     }
155 
156   return _(&msgstr[msgidx[(unsigned int) error < nmsgidx
157 			  ? error : DWFL_E_UNKNOWN_ERROR]]);
158 }
159 INTDEF (dwfl_errmsg)
160