jpeg/jerror.c

   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 /*
  22  * This file has been modified for the Mozilla/Netscape environment.
  23  * Modifications are distributed under the mozilla.org tri-license and are
  24  * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
  25  * Reserved. See http://www.mozilla.org/MPL/
  26  */
  27
  28 /* this is not a core library module, so it doesn't define JPEG_INTERNALS */
  29 #include "jinclude.h"
  30 #include "jpeglib.h"
  31 #include "jversion.h"
  32 #include "jerror.h"
  33
  34 #ifdef USE_WINDOWS_MESSAGEBOX
  35 #include <windows.h>
  36 #endif
  37
  38 #ifndef EXIT_FAILURE            /* define exit() codes if not provided */
  39 #define EXIT_FAILURE  1
  40 #endif
  41
  42
  43 /*
  44  * Create the message string table.
  45  * We do this from the master message list in jerror.h by re-reading
  46  * jerror.h with a suitable definition for macro JMESSAGE.
  47  * The message table is made an external symbol just in case any applications
  48  * want to refer to it directly.
  49  */
  50
  51 #ifdef NEED_SHORT_EXTERNAL_NAMES
  52 #define jpeg_std_message_table  jMsgTable
  53 #endif
  54
  55 #define JMESSAGE(code,string)   string ,
  56
  57 const char * const jpeg_std_message_table[] = {
  58 #include "jerror.h"
  59   NULL
  60 };
  61
  62
  63 /*
  64  * Error exit handler: must not return to caller.
  65  *
  66  * Applications may override this if they want to get control back after
  67  * an error.  Typically one would longjmp somewhere instead of exiting.
  68  * The setjmp buffer can be made a private field within an expanded error
  69  * handler object.  Note that the info needed to generate an error message
  70  * is stored in the error object, so you can generate the message now or
  71  * later, at your convenience.
  72  * You should make sure that the JPEG object is cleaned up (with jpeg_abort
  73  * or jpeg_destroy) at some point.
  74  */
  75
  76 METHODDEF(void)
  77 error_exit (j_common_ptr cinfo)
  78 {
  79   /* Always display the message */
  80   (*cinfo->err->output_message) (cinfo);
  81
  82   /* Let the memory manager delete any temp files before we die */
  83   jpeg_destroy(cinfo);
  84
  85 /* Mozilla mod: in some Windows environments, the exit() function doesn't
  86  * even exist, so don't compile a reference to it.  Heaven help you if
  87  * you fail to provide a replacement error_exit function, because the
  88  * IJG library will NOT handle control returning from error_exit!
  89  */
  90
  91 #ifndef XP_WIN
  92   exit(EXIT_FAILURE);
  93 #endif
  94 }
  95
  96
  97 /*
  98  * Actual output of an error or trace message.
  99  * Applications may override this method to send JPEG messages somewhere
 100  * other than stderr.
 101  *
 102  * On Windows, printing to stderr is generally completely useless,
 103  * so we provide optional code to produce an error-dialog popup.
 104  * Most Windows applications will still prefer to override this routine,
 105  * but if they don't, it'll do something at least marginally useful.
 106  *
 107  * NOTE: to use the library in an environment that doesn't support the
 108  * C stdio library, you may have to delete the call to fprintf() entirely,
 109  * not just not use this routine.
 110  */
 111
 112 METHODDEF(void)
 113 output_message (j_common_ptr cinfo)
 114 {
 115   char buffer[JMSG_LENGTH_MAX];
 116
 117   /* Create the message */
 118   (*cinfo->err->format_message) (cinfo, buffer);
 119 }
 120
 121
 122 /*
 123  * Decide whether to emit a trace or warning message.
 124  * msg_level is one of:
 125  *   -1: recoverable corrupt-data warning, may want to abort.
 126  *    0: important advisory messages (always display to user).
 127  *    1: first level of tracing detail.
 128  *    2,3,...: successively more detailed tracing messages.
 129  * An application might override this method if it wanted to abort on warnings
 130  * or change the policy about which messages to display.
 131  */
 132
 133 METHODDEF(void)
 134 emit_message (j_common_ptr cinfo, int msg_level)
 135 {
 136   struct jpeg_error_mgr * err = cinfo->err;
 137
 138   if (msg_level < 0) {
 139     /* It's a warning message.  Since corrupt files may generate many warnings,
 140      * the policy implemented here is to show only the first warning,
 141      * unless trace_level >= 3.
 142      */
 143     if (err->num_warnings == 0 || err->trace_level >= 3)
 144       (*err->output_message) (cinfo);
 145     /* Always count warnings in num_warnings. */
 146     err->num_warnings++;
 147   } else {
 148     /* It's a trace message.  Show it if trace_level >= msg_level. */
 149     if (err->trace_level >= msg_level)
 150       (*err->output_message) (cinfo);
 151   }
 152 }
 153
 154
 155 /*
 156  * Format a message string for the most recent JPEG error or message.
 157  * The message is stored into buffer, which should be at least JMSG_LENGTH_MAX
 158  * characters.  Note that no '\n' character is added to the string.
 159  * Few applications should need to override this method.
 160  */
 161
 162 METHODDEF(void)
 163 format_message (j_common_ptr cinfo, char * buffer)
 164 {
 165   struct jpeg_error_mgr * err = cinfo->err;
 166   int msg_code = err->msg_code;
 167   const char * msgtext = NULL;
 168   const char * msgptr;
 169   char ch;
 170   boolean isstring;
 171
 172   /* Look up message string in proper table */
 173   if (msg_code > 0 && msg_code <= err->last_jpeg_message) {
 174     msgtext = err->jpeg_message_table[msg_code];
 175   } else if (err->addon_message_table != NULL &&
 176              msg_code >= err->first_addon_message &&
 177              msg_code <= err->last_addon_message) {
 178     msgtext = err->addon_message_table[msg_code - err->first_addon_message];
 179   }
 180
 181   /* Defend against bogus message number */
 182   if (msgtext == NULL) {
 183     err->msg_parm.i[0] = msg_code;
 184     msgtext = err->jpeg_message_table[0];
 185   }
 186
 187   /* Check for string parameter, as indicated by %s in the message text */
 188   isstring = FALSE;
 189   msgptr = msgtext;
 190   while ((ch = *msgptr++) != '\0') {
 191     if (ch == '%') {
 192       if (*msgptr == 's') isstring = TRUE;
 193       break;
 194     }
 195   }
 196
 197   /* Format the message into the passed buffer */
 198   if (isstring)
 199     sprintf(buffer, msgtext, err->msg_parm.s);
 200   else
 201     sprintf(buffer, msgtext,
 202             err->msg_parm.i[0], err->msg_parm.i[1],
 203             err->msg_parm.i[2], err->msg_parm.i[3],
 204             err->msg_parm.i[4], err->msg_parm.i[5],
 205             err->msg_parm.i[6], err->msg_parm.i[7]);
 206 }
 207
 208
 209 /*
 210  * Reset error state variables at start of a new image.
 211  * This is called during compression startup to reset trace/error
 212  * processing to default state, without losing any application-specific
 213  * method pointers.  An application might possibly want to override
 214  * this method if it has additional error processing state.
 215  */
 216
 217 METHODDEF(void)
 218 reset_error_mgr (j_common_ptr cinfo)
 219 {
 220   cinfo->err->num_warnings = 0;
 221   /* trace_level is not reset since it is an application-supplied parameter */
 222   cinfo->err->msg_code = 0;     /* may be useful as a flag for "no error" */
 223 }
 224
 225
 226 /*
 227  * Fill in the standard error-handling methods in a jpeg_error_mgr object.
 228  * Typical call is:
 229  *      struct jpeg_compress_struct cinfo;
 230  *      struct jpeg_error_mgr err;
 231  *
 232  *      cinfo.err = jpeg_std_error(&err);
 233  * after which the application may override some of the methods.
 234  */
 235
 236 GLOBAL(struct jpeg_error_mgr *)
 237 jpeg_std_error (struct jpeg_error_mgr * err)
 238 {
 239   err->error_exit = error_exit;
 240   err->emit_message = emit_message;
 241   err->output_message = output_message;
 242   err->format_message = format_message;
 243   err->reset_error_mgr = reset_error_mgr;
 244
 245   err->trace_level = 0;         /* default = no tracing */
 246   err->num_warnings = 0;        /* no warnings emitted yet */
 247   err->msg_code = 0;            /* may be useful as a flag for "no error" */
 248
 249   /* Initialize message table pointers */
 250   err->jpeg_message_table = jpeg_std_message_table;
 251   err->last_jpeg_message = (int) JMSG_LASTMSGCODE - 1;
 252
 253   err->addon_message_table = NULL;
 254   err->first_addon_message = 0; /* for safety */
 255   err->last_addon_message = 0;
 256
 257   return err;
 258 }