1/*
2 * jerror.c
3 *
4 * Copyright (C) 1991-1998, Thomas G. Lane.
5 * This file is part of the Independent JPEG Group's software.
6 * For conditions of distribution and use, see the accompanying README file.
7 *
8 * This file contains simple error-reporting and trace-message routines.
9 * These are suitable for Unix-like systems and others where writing to
10 * stderr is the right thing to do. Many applications will want to replace
11 * some or all of these routines.
12 *
13 * If you define USE_WINDOWS_MESSAGEBOX in jconfig.h or in the makefile,
14 * you get a Windows-specific hack to display error messages in a dialog box.
15 * It ain't much, but it beats dropping error messages into the bit bucket,
16 * which is what happens to output to stderr under most Windows C compilers.
17 *
18 * These routines are used by both the compression and decompression code.
19 */
20
21/* this is not a core library module, so it doesn't define JPEG_INTERNALS */
22#include "jinclude.h"
23#include "jpeglib.h"
24#include "jversion.h"
25#include "jerror.h"
26
27#ifdef USE_WINDOWS_MESSAGEBOX
28#include <windows.h>
29#endif
30
31#ifndef EXIT_FAILURE /* define exit() codes if not provided */
32#define EXIT_FAILURE 1
33#endif
34
35
36/*
37 * Create the message string table.
38 * We do this from the master message list in jerror.h by re-reading
39 * jerror.h with a suitable definition for macro JMESSAGE.
40 * The message table is made an external symbol just in case any applications
41 * want to refer to it directly.
42 */
43
44#ifdef NEED_SHORT_EXTERNAL_NAMES
45#define jpeg_std_message_table jMsgTable
46#endif
47
48#define JMESSAGE(code,string) string ,
49
50const char * const jpeg_std_message_table[] = {
51#include "jerror.h"
52 NULL
53};
54
55
56/*
57 * Error exit handler: must not return to caller.
58 *
59 * Applications may override this if they want to get control back after
60 * an error. Typically one would longjmp somewhere instead of exiting.
61 * The setjmp buffer can be made a private field within an expanded error
62 * handler object. Note that the info needed to generate an error message
63 * is stored in the error object, so you can generate the message now or
64 * later, at your convenience.
65 * You should make sure that the JPEG object is cleaned up (with jpeg_abort
66 * or jpeg_destroy) at some point.
67 */
68
69METHODDEF(void)
70error_exit (j_common_ptr cinfo)
71{
72 /* Always display the message */
73 (*cinfo->err->output_message) (cinfo);
74
75 /* Let the memory manager delete any temp files before we die */
76 jpeg_destroy(cinfo);
77
78 exit(EXIT_FAILURE);
79}
80
81
82/*
83 * Actual output of an error or trace message.
84 * Applications may override this method to send JPEG messages somewhere
85 * other than stderr.
86 *
87 * On Windows, printing to stderr is generally completely useless,
88 * so we provide optional code to produce an error-dialog popup.
89 * Most Windows applications will still prefer to override this routine,
90 * but if they don't, it'll do something at least marginally useful.
91 *
92 * NOTE: to use the library in an environment that doesn't support the
93 * C stdio library, you may have to delete the call to fprintf() entirely,
94 * not just not use this routine.
95 */
96
97METHODDEF(void)
98output_message (j_common_ptr cinfo)
99{
100 char buffer[JMSG_LENGTH_MAX];
101
102 /* Create the message */
103 (*cinfo->err->format_message) (cinfo, buffer);
104
105#ifdef USE_WINDOWS_MESSAGEBOX
106 /* Display it in a message dialog box */
107 MessageBox(GetActiveWindow(), buffer, "JPEG Library Error",
108 MB_OK | MB_ICONERROR);
109#else
110 /* Send it to stderr, adding a newline */
111 fprintf(stderr, "%s\n", buffer);
112#endif
113}
114
115
116/*
117 * Decide whether to emit a trace or warning message.
118 * msg_level is one of:
119 * -1: recoverable corrupt-data warning, may want to abort.
120 * 0: important advisory messages (always display to user).
121 * 1: first level of tracing detail.
122 * 2,3,...: successively more detailed tracing messages.
123 * An application might override this method if it wanted to abort on warnings
124 * or change the policy about which messages to display.
125 */
126
127METHODDEF(void)
128emit_message (j_common_ptr cinfo, int msg_level)
129{
130 struct jpeg_error_mgr * err = cinfo->err;
131
132 if (msg_level < 0) {
133 /* It's a warning message. Since corrupt files may generate many warnings,
134 * the policy implemented here is to show only the first warning,
135 * unless trace_level >= 3.
136 */
137 if (err->num_warnings == 0 || err->trace_level >= 3)
138 (*err->output_message) (cinfo);
139 /* Always count warnings in num_warnings. */
140 err->num_warnings++;
141 } else {
142 /* It's a trace message. Show it if trace_level >= msg_level. */
143 if (err->trace_level >= msg_level)
144 (*err->output_message) (cinfo);
145 }
146}
147
148
149/*
150 * Format a message string for the most recent JPEG error or message.
151 * The message is stored into buffer, which should be at least JMSG_LENGTH_MAX
152 * characters. Note that no '\n' character is added to the string.
153 * Few applications should need to override this method.
154 */
155
156METHODDEF(void)
157format_message (j_common_ptr cinfo, char * buffer)
158{
159 struct jpeg_error_mgr * err = cinfo->err;
160 int msg_code = err->msg_code;
161 const char * msgtext = NULL;
162 const char * msgptr;
163 char ch;
164 boolean isstring;
165
166 /* Look up message string in proper table */
167 if (msg_code > 0 && msg_code <= err->last_jpeg_message) {
168 msgtext = err->jpeg_message_table[msg_code];
169 } else if (err->addon_message_table != NULL &&
170 msg_code >= err->first_addon_message &&
171 msg_code <= err->last_addon_message) {
172 msgtext = err->addon_message_table[msg_code - err->first_addon_message];
173 }
174
175 /* Defend against bogus message number */
176 if (msgtext == NULL) {
177 err->msg_parm.i[0] = msg_code;
178 msgtext = err->jpeg_message_table[0];
179 }
180
181 /* Check for string parameter, as indicated by %s in the message text */
182 isstring = FALSE;
183 msgptr = msgtext;
184 while ((ch = *msgptr++) != '\0') {
185 if (ch == '%') {
186 if (*msgptr == 's') isstring = TRUE;
187 break;
188 }
189 }
190
191 /* Format the message into the passed buffer */
192 if (isstring)
193 sprintf(buffer, msgtext, err->msg_parm.s);
194 else
195 sprintf(buffer, msgtext,
196 err->msg_parm.i[0], err->msg_parm.i[1],
197 err->msg_parm.i[2], err->msg_parm.i[3],
198 err->msg_parm.i[4], err->msg_parm.i[5],
199 err->msg_parm.i[6], err->msg_parm.i[7]);
200}
201
202
203/*
204 * Reset error state variables at start of a new image.
205 * This is called during compression startup to reset trace/error
206 * processing to default state, without losing any application-specific
207 * method pointers. An application might possibly want to override
208 * this method if it has additional error processing state.
209 */
210
211METHODDEF(void)
212reset_error_mgr (j_common_ptr cinfo)
213{
214 cinfo->err->num_warnings = 0;
215 /* trace_level is not reset since it is an application-supplied parameter */
216 cinfo->err->msg_code = 0; /* may be useful as a flag for "no error" */
217}
218
219
220/*
221 * Fill in the standard error-handling methods in a jpeg_error_mgr object.
222 * Typical call is:
223 * struct jpeg_compress_struct cinfo;
224 * struct jpeg_error_mgr err;
225 *
226 * cinfo.err = jpeg_std_error(&err);
227 * after which the application may override some of the methods.
228 */
229
230GLOBAL(struct jpeg_error_mgr *)
231jpeg_std_error (struct jpeg_error_mgr * err)
232{
233 err->error_exit = error_exit;
234 err->emit_message = emit_message;
235 err->output_message = output_message;
236 err->format_message = format_message;
237 err->reset_error_mgr = reset_error_mgr;
238
239 err->trace_level = 0; /* default = no tracing */
240 err->num_warnings = 0; /* no warnings emitted yet */
241 err->msg_code = 0; /* may be useful as a flag for "no error" */
242
243 /* Initialize message table pointers */
244 err->jpeg_message_table = jpeg_std_message_table;
245 err->last_jpeg_message = (int) JMSG_LASTMSGCODE - 1;
246
247 err->addon_message_table = NULL;
248 err->first_addon_message = 0; /* for safety */
249 err->last_addon_message = 0;
250
251 return err;
252}
253