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 

    50 const 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 

    69 METHODDEF(void)

    70 error_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 

    97 METHODDEF(void)

    98 output_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 

   127 METHODDEF(void)

   128 emit_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 

   156 METHODDEF(void)

   157 format_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 

   211 METHODDEF(void)

   212 reset_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 

   230 GLOBAL(struct jpeg_error_mgr *)

   231 jpeg_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 }