1 /*

     2  * reserved comment block

     3  * DO NOT REMOVE OR ALTER!

     4  */

     5 /*

     6  * jerror.c

     7  *

     8  * Copyright (C) 1991-1998, Thomas G. Lane.

     9  * This file is part of the Independent JPEG Group's software.

    10  * For conditions of distribution and use, see the accompanying README file.

    11  *

    12  * This file contains simple error-reporting and trace-message routines.

    13  * These are suitable for Unix-like systems and others where writing to

    14  * stderr is the right thing to do.  Many applications will want to replace

    15  * some or all of these routines.

    16  *

    17  * If you define USE_WINDOWS_MESSAGEBOX in jconfig.h or in the makefile,

    18  * you get a Windows-specific hack to display error messages in a dialog box.

    19  * It ain't much, but it beats dropping error messages into the bit bucket,

    20  * which is what happens to output to stderr under most Windows C compilers.

    21  *

    22  * These routines are used by both the compression and decompression code.

    23  */

    24 

    25 /* this is not a core library module, so it doesn't define JPEG_INTERNALS */

    26 #include "jinclude.h"

    27 #include "jpeglib.h"

    28 #include "jversion.h"

    29 #include "jerror.h"

    30 

    31 #ifdef USE_WINDOWS_MESSAGEBOX

    32 #include <windows.h>

    33 #endif

    34 

    35 #ifndef EXIT_FAILURE            /* define exit() codes if not provided */

    36 #define EXIT_FAILURE  1

    37 #endif

    38 

    39 

    40 /*

    41  * Create the message string table.

    42  * We do this from the master message list in jerror.h by re-reading

    43  * jerror.h with a suitable definition for macro JMESSAGE.

    44  * The message table is made an external symbol just in case any applications

    45  * want to refer to it directly.

    46  */

    47 

    48 #ifdef NEED_SHORT_EXTERNAL_NAMES

    49 #define jpeg_std_message_table  jMsgTable

    50 #endif

    51 

    52 #define JMESSAGE(code,string)   string ,

    53 

    54 const char * const jpeg_std_message_table[] = {

    55 #include "jerror.h"

    56   NULL

    57 };

    58 

    59 

    60 /*

    61  * Error exit handler: must not return to caller.

    62  *

    63  * Applications may override this if they want to get control back after

    64  * an error.  Typically one would longjmp somewhere instead of exiting.

    65  * The setjmp buffer can be made a private field within an expanded error

    66  * handler object.  Note that the info needed to generate an error message

    67  * is stored in the error object, so you can generate the message now or

    68  * later, at your convenience.

    69  * You should make sure that the JPEG object is cleaned up (with jpeg_abort

    70  * or jpeg_destroy) at some point.

    71  */

    72 

    73 METHODDEF(void)

    74 error_exit (j_common_ptr cinfo)

    75 {

    76   /* Always display the message */

    77   (*cinfo->err->output_message) (cinfo);

    78 

    79   /* Let the memory manager delete any temp files before we die */

    80   jpeg_destroy(cinfo);

    81 

    82   /*

    83    * This should never happen since the Java library replaces the

    84    * error_exit pointer in the error handler structs it uses.

    85    *

    86    * exit(EXIT_FAILURE);

    87    */

    88 }

    89 

    90 

    91 /*

    92  * Actual output of an error or trace message.

    93  * Applications may override this method to send JPEG messages somewhere

    94  * other than stderr.

    95  *

    96  * On Windows, printing to stderr is generally completely useless,

    97  * so we provide optional code to produce an error-dialog popup.

    98  * Most Windows applications will still prefer to override this routine,

    99  * but if they don't, it'll do something at least marginally useful.

   100  *

   101  * NOTE: to use the library in an environment that doesn't support the

   102  * C stdio library, you may have to delete the call to fprintf() entirely,

   103  * not just not use this routine.

   104  */

   105 

   106 METHODDEF(void)

   107 output_message (j_common_ptr cinfo)

   108 {

   109   char buffer[JMSG_LENGTH_MAX];

   110 

   111   /* Create the message */

   112   (*cinfo->err->format_message) (cinfo, buffer);

   113 

   114 #ifdef USE_WINDOWS_MESSAGEBOX

   115   /* Display it in a message dialog box */

   116   MessageBox(GetActiveWindow(), buffer, "JPEG Library Error",

   117              MB_OK | MB_ICONERROR);

   118 #else

   119   /* Send it to stderr, adding a newline */

   120   fprintf(stderr, "%s\n", buffer);

   121 #endif

   122 }

   123 

   124 

   125 /*

   126  * Decide whether to emit a trace or warning message.

   127  * msg_level is one of:

   128  *   -1: recoverable corrupt-data warning, may want to abort.

   129  *    0: important advisory messages (always display to user).

   130  *    1: first level of tracing detail.

   131  *    2,3,...: successively more detailed tracing messages.

   132  * An application might override this method if it wanted to abort on warnings

   133  * or change the policy about which messages to display.

   134  */

   135 

   136 METHODDEF(void)

   137 emit_message (j_common_ptr cinfo, int msg_level)

   138 {

   139   struct jpeg_error_mgr * err = cinfo->err;

   140 

   141   if (msg_level < 0) {

   142     /* It's a warning message.  Since corrupt files may generate many warnings,

   143      * the policy implemented here is to show only the first warning,

   144      * unless trace_level >= 3.

   145      */

   146     if (err->num_warnings == 0 || err->trace_level >= 3)

   147       (*err->output_message) (cinfo);

   148     /* Always count warnings in num_warnings. */

   149     err->num_warnings++;

   150   } else {

   151     /* It's a trace message.  Show it if trace_level >= msg_level. */

   152     if (err->trace_level >= msg_level)

   153       (*err->output_message) (cinfo);

   154   }

   155 }

   156 

   157 

   158 /*

   159  * Format a message string for the most recent JPEG error or message.

   160  * The message is stored into buffer, which should be at least JMSG_LENGTH_MAX

   161  * characters.  Note that no '\n' character is added to the string.

   162  * Few applications should need to override this method.

   163  */

   164 

   165 METHODDEF(void)

   166 format_message (j_common_ptr cinfo, char * buffer)

   167 {

   168 

   169 /* Had to kill this function altogether

   170    to avoid linking to VM when building the splash screen with static libjpeg */

   171 

   172 #ifndef SPLASHSCREEN

   173   int jio_snprintf(char *str, size_t count, const char *fmt, ...);

   174   struct jpeg_error_mgr * err = cinfo->err;

   175   int msg_code = err->msg_code;

   176   const char * msgtext = NULL;

   177   const char * msgptr;

   178   char ch;

   179   boolean isstring;

   180 

   181   /* Look up message string in proper table */

   182   if (msg_code > 0 && msg_code <= err->last_jpeg_message) {

   183     msgtext = err->jpeg_message_table[msg_code];

   184   } else if (err->addon_message_table != NULL &&

   185              msg_code >= err->first_addon_message &&

   186              msg_code <= err->last_addon_message) {

   187     msgtext = err->addon_message_table[msg_code - err->first_addon_message];

   188   }

   189 

   190   /* Defend against bogus message number */

   191   if (msgtext == NULL) {

   192     err->msg_parm.i[0] = msg_code;

   193     msgtext = err->jpeg_message_table[0];

   194   }

   195 

   196   /* Check for string parameter, as indicated by %s in the message text */

   197   isstring = FALSE;

   198   msgptr = msgtext;

   199   while ((ch = *msgptr++) != '\0') {

   200     if (ch == '%') {

   201       if (*msgptr == 's') isstring = TRUE;

   202       break;

   203     }

   204   }

   205 

   206   /* Format the message into the passed buffer */

   207   if (isstring)

   208     /* Buffer size is JMSG_LENGTH_MAX, quietly truncate on overflow */

   209     (void) jio_snprintf(buffer, JMSG_LENGTH_MAX, msgtext, err->msg_parm.s);

   210   else

   211     /* Buffer size is JMSG_LENGTH_MAX, quietly truncate on overflow */

   212     (void) jio_snprintf(buffer, JMSG_LENGTH_MAX, msgtext,

   213                         err->msg_parm.i[0], err->msg_parm.i[1],

   214                         err->msg_parm.i[2], err->msg_parm.i[3],

   215                         err->msg_parm.i[4], err->msg_parm.i[5],

   216                         err->msg_parm.i[6], err->msg_parm.i[7]);

   217 #else /* SPLASHSCREEN */

   218         *buffer = '\0';

   219 #endif /* SPLASHSCREEN */

   220 }

   221 

   222 

   223 /*

   224  * Reset error state variables at start of a new image.

   225  * This is called during compression startup to reset trace/error

   226  * processing to default state, without losing any application-specific

   227  * method pointers.  An application might possibly want to override

   228  * this method if it has additional error processing state.

   229  */

   230 

   231 METHODDEF(void)

   232 reset_error_mgr (j_common_ptr cinfo)

   233 {

   234   cinfo->err->num_warnings = 0;

   235   /* trace_level is not reset since it is an application-supplied parameter */

   236   cinfo->err->msg_code = 0;     /* may be useful as a flag for "no error" */

   237 }

   238 

   239 

   240 /*

   241  * Fill in the standard error-handling methods in a jpeg_error_mgr object.

   242  * Typical call is:

   243  *      struct jpeg_compress_struct cinfo;

   244  *      struct jpeg_error_mgr err;

   245  *

   246  *      cinfo.err = jpeg_std_error(&err);

   247  * after which the application may override some of the methods.

   248  */

   249 

   250 GLOBAL(struct jpeg_error_mgr *)

   251 jpeg_std_error (struct jpeg_error_mgr * err)

   252 {

   253   err->error_exit = error_exit;

   254   err->emit_message = emit_message;

   255   err->output_message = output_message;

   256   err->format_message = format_message;

   257   err->reset_error_mgr = reset_error_mgr;

   258 

   259   err->trace_level = 0;         /* default = no tracing */

   260   err->num_warnings = 0;        /* no warnings emitted yet */

   261   err->msg_code = 0;            /* may be useful as a flag for "no error" */

   262 

   263   /* Initialize message table pointers */

   264   err->jpeg_message_table = jpeg_std_message_table;

   265   err->last_jpeg_message = (int) JMSG_LASTMSGCODE - 1;

   266 

   267   err->addon_message_table = NULL;

   268   err->first_addon_message = 0; /* for safety */

   269   err->last_addon_message = 0;

   270 

   271   return err;

   272 }