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.
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.
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.
18 * These routines are used by both the compression and decompression code.
21 /* this is not a core library module, so it doesn't define JPEG_INTERNALS */
27 #ifdef USE_WINDOWS_MESSAGEBOX
31 #ifndef EXIT_FAILURE /* define exit() codes if not provided */
32 #define EXIT_FAILURE 1
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.
44 #ifdef NEED_SHORT_EXTERNAL_NAMES
45 #define jpeg_std_message_table jMsgTable
48 #define JMESSAGE(code,string) string ,
50 const char * const jpeg_std_message_table
[] = {
57 * Error exit handler: must not return to caller.
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.
70 error_exit (j_common_ptr cinfo
)
72 /* Always display the message */
73 (*cinfo
->err
->output_message
) (cinfo
);
75 /* Let the memory manager delete any temp files before we die */
83 * Actual output of an error or trace message.
84 * Applications may override this method to send JPEG messages somewhere
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.
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.
98 output_message (j_common_ptr cinfo
)
100 char buffer
[JMSG_LENGTH_MAX
];
102 /* Create the message */
103 (*cinfo
->err
->format_message
) (cinfo
, buffer
);
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
);
110 /* Send it to stderr, adding a newline */
111 fprintf(stderr
, "%s\n", buffer
);
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.
128 emit_message (j_common_ptr cinfo
, int msg_level
)
130 struct jpeg_error_mgr
* err
= cinfo
->err
;
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.
137 if (err
->num_warnings
== 0 || err
->trace_level
>= 3)
138 (*err
->output_message
) (cinfo
);
139 /* Always count warnings in num_warnings. */
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
);
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.
157 format_message (j_common_ptr cinfo
, char * buffer
)
159 struct jpeg_error_mgr
* err
= cinfo
->err
;
160 int msg_code
= err
->msg_code
;
161 const char * msgtext
= NULL
;
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
];
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];
181 /* Check for string parameter, as indicated by %s in the message text */
184 while ((ch
= *msgptr
++) != '\0') {
186 if (*msgptr
== 's') isstring
= TRUE
;
191 /* Format the message into the passed buffer */
193 sprintf(buffer
, msgtext
, err
->msg_parm
.s
);
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]);
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.
212 reset_error_mgr (j_common_ptr cinfo
)
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" */
221 * Fill in the standard error-handling methods in a jpeg_error_mgr object.
223 * struct jpeg_compress_struct cinfo;
224 * struct jpeg_error_mgr err;
226 * cinfo.err = jpeg_std_error(&err);
227 * after which the application may override some of the methods.
230 GLOBAL(struct jpeg_error_mgr
*)
231 jpeg_std_error (struct jpeg_error_mgr
* err
)
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
;
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" */
243 /* Initialize message table pointers */
244 err
->jpeg_message_table
= jpeg_std_message_table
;
245 err
->last_jpeg_message
= (int) JMSG_LASTMSGCODE
- 1;
247 err
->addon_message_table
= NULL
;
248 err
->first_addon_message
= 0; /* for safety */
249 err
->last_addon_message
= 0;