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