1/* gpg-error.h - Public interface to libgpg-error.
2   Copyright (C) 2003, 2004, 2010 g10 Code GmbH
3
4   This file is part of libgpg-error.
5 
6   libgpg-error is free software; you can redistribute it and/or
7   modify it under the terms of the GNU Lesser General Public License
8   as published by the Free Software Foundation; either version 2.1 of
9   the License, or (at your option) any later version.
10 
11   libgpg-error is distributed in the hope that it will be useful, but
12   WITHOUT ANY WARRANTY; without even the implied warranty of
13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14   Lesser General Public License for more details.
15 
16   You should have received a copy of the GNU Lesser General Public
17   License along with this program; if not, see <http://www.gnu.org/licenses/>.
18 */
19
20
21#ifndef GPG_ERROR_H
22#define GPG_ERROR_H	1
23
24#include <stddef.h>
25
26#ifdef __GNUC__
27#define GPG_ERR_INLINE __inline__
28#elif __STDC_VERSION__ >= 199901L
29#define GPG_ERR_INLINE inline
30#else
31#ifndef GPG_ERR_INLINE
32#define GPG_ERR_INLINE
33#endif 
34#endif
35
36
37#ifdef __cplusplus
38extern "C" {
39#if 0 /* just to make Emacs auto-indent happy */
40}
41#endif
42#endif /* __cplusplus */
43
44/* The GnuPG project consists of many components.  Error codes are
45   exchanged between all components.  The common error codes and their
46   user-presentable descriptions are kept into a shared library to
47   allow adding new error codes and components without recompiling any
48   of the other components.  The interface will not change in a
49   backward incompatible way.
50
51   An error code together with an error source build up an error
52   value.  As the error value is been passed from one component to
53   another, it preserver the information about the source and nature
54   of the error.
55
56   A component of the GnuPG project can define the following macros to
57   tune the behaviour of the library:
58
59   GPG_ERR_SOURCE_DEFAULT: Define to an error source of type
60   gpg_err_source_t to make that source the default for gpg_error().
61   Otherwise GPG_ERR_SOURCE_UNKNOWN is used as default.
62
63   GPG_ERR_ENABLE_GETTEXT_MACROS: Define to provide macros to map the
64   internal gettext API to standard names.  This has only an effect on
65   Windows platforms.  */
66
67
68/* The error source type gpg_err_source_t.
69
70   Where as the Poo out of a welle small
71   Taketh his firste springing and his sours.
72					--Chaucer.  */
73
74/* Only use free slots, never change or reorder the existing
75   entries.  */
76typedef enum
77  {
78@include err-sources.h.in
79
80    /* This is one more than the largest allowed entry.  */
81    GPG_ERR_SOURCE_DIM = 128
82  } gpg_err_source_t;
83
84
85/* The error code type gpg_err_code_t.  */
86
87/* Only use free slots, never change or reorder the existing
88   entries.  */
89typedef enum
90  {
91@include err-codes.h.in
92
93    /* The following error codes are used to map system errors.  */
94#define GPG_ERR_SYSTEM_ERROR	(1 << 15)
95@include errnos.in
96
97    /* This is one more than the largest allowed entry.  */
98    GPG_ERR_CODE_DIM = 65536
99  } gpg_err_code_t;
100
101
102/* The error value type gpg_error_t.  */
103
104/* We would really like to use bit-fields in a struct, but using
105   structs as return values can cause binary compatibility issues, in
106   particular if you want to do it effeciently (also see
107   -freg-struct-return option to GCC).  */
108typedef unsigned int gpg_error_t;
109
110/* We use the lowest 16 bits of gpg_error_t for error codes.  The 16th
111   bit indicates system errors.  */
112#define GPG_ERR_CODE_MASK	(GPG_ERR_CODE_DIM - 1)
113
114/* Bits 17 to 24 are reserved.  */
115
116/* We use the upper 7 bits of gpg_error_t for error sources.  */
117#define GPG_ERR_SOURCE_MASK	(GPG_ERR_SOURCE_DIM - 1)
118#define GPG_ERR_SOURCE_SHIFT	24
119
120/* The highest bit is reserved.  It shouldn't be used to prevent
121   potential negative numbers when transmitting error values as
122   text.  */
123
124
125/* GCC feature test.  */
126#undef _GPG_ERR_HAVE_CONSTRUCTOR
127#if __GNUC__
128#define _GPG_ERR_GCC_VERSION (__GNUC__ * 10000 \
129                            + __GNUC_MINOR__ * 100 \
130                            + __GNUC_PATCHLEVEL__)
131
132#if _GPG_ERR_GCC_VERSION > 30100
133#define _GPG_ERR_CONSTRUCTOR	__attribute__ ((__constructor__))
134#define _GPG_ERR_HAVE_CONSTRUCTOR
135#endif
136#endif
137
138#ifndef _GPG_ERR_CONSTRUCTOR
139#define _GPG_ERR_CONSTRUCTOR
140#endif
141
142
143/* Initialization function.  */
144
145/* Initialize the library.  This function should be run early.  */
146gpg_error_t gpg_err_init (void) _GPG_ERR_CONSTRUCTOR;
147
148/* If this is defined, the library is already initialized by the
149   constructor and does not need to be initialized explicitely.  */
150#undef GPG_ERR_INITIALIZED
151#ifdef _GPG_ERR_HAVE_CONSTRUCTOR
152#define GPG_ERR_INITIALIZED	1
153#endif
154
155/* See the source on how to use the deinit function; it is usually not
156   required.  */
157void gpg_err_deinit (int mode);
158
159
160/* Constructor and accessor functions.  */
161
162/* Construct an error value from an error code and source.  Within a
163   subsystem, use gpg_error.  */
164static GPG_ERR_INLINE gpg_error_t
165gpg_err_make (gpg_err_source_t source, gpg_err_code_t code)
166{
167  return code == GPG_ERR_NO_ERROR ? GPG_ERR_NO_ERROR
168    : (((source & GPG_ERR_SOURCE_MASK) << GPG_ERR_SOURCE_SHIFT)
169       | (code & GPG_ERR_CODE_MASK));
170}
171
172
173/* The user should define GPG_ERR_SOURCE_DEFAULT before including this
174   file to specify a default source for gpg_error.  */
175#ifndef GPG_ERR_SOURCE_DEFAULT
176#define GPG_ERR_SOURCE_DEFAULT	GPG_ERR_SOURCE_UNKNOWN
177#endif
178
179static GPG_ERR_INLINE gpg_error_t
180gpg_error (gpg_err_code_t code)
181{
182  return gpg_err_make (GPG_ERR_SOURCE_DEFAULT, code);
183}
184
185
186/* Retrieve the error code from an error value.  */
187static GPG_ERR_INLINE gpg_err_code_t
188gpg_err_code (gpg_error_t err)
189{
190  return (gpg_err_code_t) (err & GPG_ERR_CODE_MASK);
191}
192
193
194/* Retrieve the error source from an error value.  */
195static GPG_ERR_INLINE gpg_err_source_t
196gpg_err_source (gpg_error_t err)
197{
198  return (gpg_err_source_t) ((err >> GPG_ERR_SOURCE_SHIFT)
199			     & GPG_ERR_SOURCE_MASK);
200}
201
202
203/* String functions.  */
204
205/* Return a pointer to a string containing a description of the error
206   code in the error value ERR.  This function is not thread-safe.  */
207const char *gpg_strerror (gpg_error_t err);
208
209/* Return the error string for ERR in the user-supplied buffer BUF of
210   size BUFLEN.  This function is, in contrast to gpg_strerror,
211   thread-safe if a thread-safe strerror_r() function is provided by
212   the system.  If the function succeeds, 0 is returned and BUF
213   contains the string describing the error.  If the buffer was not
214   large enough, ERANGE is returned and BUF contains as much of the
215   beginning of the error string as fits into the buffer.  */
216int gpg_strerror_r (gpg_error_t err, char *buf, size_t buflen);
217
218/* Return a pointer to a string containing a description of the error
219   source in the error value ERR.  */
220const char *gpg_strsource (gpg_error_t err);
221
222
223/* Mapping of system errors (errno).  */
224
225/* Retrieve the error code for the system error ERR.  This returns
226   GPG_ERR_UNKNOWN_ERRNO if the system error is not mapped (report
227   this). */
228gpg_err_code_t gpg_err_code_from_errno (int err);
229
230
231/* Retrieve the system error for the error code CODE.  This returns 0
232   if CODE is not a system error code.  */
233int gpg_err_code_to_errno (gpg_err_code_t code);
234
235
236/* Retrieve the error code directly from the ERRNO variable.  This
237   returns GPG_ERR_UNKNOWN_ERRNO if the system error is not mapped
238   (report this) and GPG_ERR_MISSING_ERRNO if ERRNO has the value 0. */
239gpg_err_code_t gpg_err_code_from_syserror (void);
240
241
242/* Set the ERRNO variable.  This function is the preferred way to set
243   ERRNO due to peculiarities on WindowsCE.  */
244void gpg_err_set_errno (int err);
245
246@include extra-h.in
247
248/* Self-documenting convenience functions.  */
249
250static GPG_ERR_INLINE gpg_error_t
251gpg_err_make_from_errno (gpg_err_source_t source, int err)
252{
253  return gpg_err_make (source, gpg_err_code_from_errno (err));
254}
255
256
257static GPG_ERR_INLINE gpg_error_t
258gpg_error_from_errno (int err)
259{
260  return gpg_error (gpg_err_code_from_errno (err));
261}
262
263static GPG_ERR_INLINE gpg_error_t
264gpg_error_from_syserror (void)
265{
266  return gpg_error (gpg_err_code_from_syserror ());
267}
268
269#ifdef __cplusplus
270}
271#endif
272
273
274#endif	/* GPG_ERROR_H */
275