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