vx32

jerror.c (7801B)

---

 /*
  * jerror.c
  *
  * Copyright (C) 1991-1998, Thomas G. Lane.
  * This file is part of the Independent JPEG Group's software.
  * For conditions of distribution and use, see the accompanying README file.
  *
  * This file contains simple error-reporting and trace-message routines.
  * These are suitable for Unix-like systems and others where writing to
  * stderr is the right thing to do.  Many applications will want to replace
  * some or all of these routines.
  *
  * If you define USE_WINDOWS_MESSAGEBOX in jconfig.h or in the makefile,
  * you get a Windows-specific hack to display error messages in a dialog box.
  * It ain't much, but it beats dropping error messages into the bit bucket,
  * which is what happens to output to stderr under most Windows C compilers.
  *
  * These routines are used by both the compression and decompression code.
  */
 
 /* this is not a core library module, so it doesn't define JPEG_INTERNALS */
 #include "jinclude.h"
 #include "jpeglib.h"
 #include "jversion.h"
 #include "jerror.h"
 
 #ifdef USE_WINDOWS_MESSAGEBOX
 #include <windows.h>
 #endif
 
 #ifndef EXIT_FAILURE		/* define exit() codes if not provided */
 #define EXIT_FAILURE  1
 #endif
 
 
 /*
  * Create the message string table.
  * We do this from the master message list in jerror.h by re-reading
  * jerror.h with a suitable definition for macro JMESSAGE.
  * The message table is made an external symbol just in case any applications
  * want to refer to it directly.
  */
 
 #ifdef NEED_SHORT_EXTERNAL_NAMES
 #define jpeg_std_message_table	jMsgTable
 #endif
 
 #define JMESSAGE(code,string)	string ,
 
 const char * const jpeg_std_message_table[] = {
 #include "jerror.h"
   NULL
 };
 
 
 /*
  * Error exit handler: must not return to caller.
  *
  * Applications may override this if they want to get control back after
  * an error.  Typically one would longjmp somewhere instead of exiting.
  * The setjmp buffer can be made a private field within an expanded error
  * handler object.  Note that the info needed to generate an error message
  * is stored in the error object, so you can generate the message now or
  * later, at your convenience.
  * You should make sure that the JPEG object is cleaned up (with jpeg_abort
  * or jpeg_destroy) at some point.
  */
 
 METHODDEF(void)
 error_exit (j_common_ptr cinfo)
 {
   /* Always display the message */
   (*cinfo->err->output_message) (cinfo);
 
   /* Let the memory manager delete any temp files before we die */
   jpeg_destroy(cinfo);
 
   exit(EXIT_FAILURE);
 }
 
 
 /*
  * Actual output of an error or trace message.
  * Applications may override this method to send JPEG messages somewhere
  * other than stderr.
  *
  * On Windows, printing to stderr is generally completely useless,
  * so we provide optional code to produce an error-dialog popup.
  * Most Windows applications will still prefer to override this routine,
  * but if they don't, it'll do something at least marginally useful.
  *
  * NOTE: to use the library in an environment that doesn't support the
  * C stdio library, you may have to delete the call to fprintf() entirely,
  * not just not use this routine.
  */
 
 METHODDEF(void)
 output_message (j_common_ptr cinfo)
 {
   char buffer[JMSG_LENGTH_MAX];
 
   /* Create the message */
   (*cinfo->err->format_message) (cinfo, buffer);
 
 #ifdef USE_WINDOWS_MESSAGEBOX
   /* Display it in a message dialog box */
   MessageBox(GetActiveWindow(), buffer, "JPEG Library Error",
 	     MB_OK | MB_ICONERROR);
 #else
   /* Send it to stderr, adding a newline */
   fprintf(stderr, "%s\n", buffer);
 #endif
 }
 
 
 /*
  * Decide whether to emit a trace or warning message.
  * msg_level is one of:
  *   -1: recoverable corrupt-data warning, may want to abort.
  *    0: important advisory messages (always display to user).
  *    1: first level of tracing detail.
  *    2,3,...: successively more detailed tracing messages.
  * An application might override this method if it wanted to abort on warnings
  * or change the policy about which messages to display.
  */
 
 METHODDEF(void)
 emit_message (j_common_ptr cinfo, int msg_level)
 {
   struct jpeg_error_mgr * err = cinfo->err;
 
   if (msg_level < 0) {
     /* It's a warning message.  Since corrupt files may generate many warnings,
      * the policy implemented here is to show only the first warning,
      * unless trace_level >= 3.
      */
     if (err->num_warnings == 0 || err->trace_level >= 3)
       (*err->output_message) (cinfo);
     /* Always count warnings in num_warnings. */
     err->num_warnings++;
   } else {
     /* It's a trace message.  Show it if trace_level >= msg_level. */
     if (err->trace_level >= msg_level)
       (*err->output_message) (cinfo);
   }
 }
 
 
 /*
  * Format a message string for the most recent JPEG error or message.
  * The message is stored into buffer, which should be at least JMSG_LENGTH_MAX
  * characters.  Note that no '\n' character is added to the string.
  * Few applications should need to override this method.
  */
 
 METHODDEF(void)
 format_message (j_common_ptr cinfo, char * buffer)
 {
   struct jpeg_error_mgr * err = cinfo->err;
   int msg_code = err->msg_code;
   const char * msgtext = NULL;
   const char * msgptr;
   char ch;
   boolean isstring;
 
   /* Look up message string in proper table */
   if (msg_code > 0 && msg_code <= err->last_jpeg_message) {
     msgtext = err->jpeg_message_table[msg_code];
   } else if (err->addon_message_table != NULL &&
 	     msg_code >= err->first_addon_message &&
 	     msg_code <= err->last_addon_message) {
     msgtext = err->addon_message_table[msg_code - err->first_addon_message];
   }
 
   /* Defend against bogus message number */
   if (msgtext == NULL) {
     err->msg_parm.i[0] = msg_code;
     msgtext = err->jpeg_message_table[0];
   }
 
   /* Check for string parameter, as indicated by %s in the message text */
   isstring = FALSE;
   msgptr = msgtext;
   while ((ch = *msgptr++) != '\0') {
     if (ch == '%') {
       if (*msgptr == 's') isstring = TRUE;
       break;
     }
   }
 
   /* Format the message into the passed buffer */
   if (isstring)
     sprintf(buffer, msgtext, err->msg_parm.s);
   else
     sprintf(buffer, msgtext,
 	    err->msg_parm.i[0], err->msg_parm.i[1],
 	    err->msg_parm.i[2], err->msg_parm.i[3],
 	    err->msg_parm.i[4], err->msg_parm.i[5],
 	    err->msg_parm.i[6], err->msg_parm.i[7]);
 }
 
 
 /*
  * Reset error state variables at start of a new image.
  * This is called during compression startup to reset trace/error
  * processing to default state, without losing any application-specific
  * method pointers.  An application might possibly want to override
  * this method if it has additional error processing state.
  */
 
 METHODDEF(void)
 reset_error_mgr (j_common_ptr cinfo)
 {
   cinfo->err->num_warnings = 0;
   /* trace_level is not reset since it is an application-supplied parameter */
   cinfo->err->msg_code = 0;	/* may be useful as a flag for "no error" */
 }
 
 
 /*
  * Fill in the standard error-handling methods in a jpeg_error_mgr object.
  * Typical call is:
  *	struct jpeg_compress_struct cinfo;
  *	struct jpeg_error_mgr err;
  *
  *	cinfo.err = jpeg_std_error(&err);
  * after which the application may override some of the methods.
  */
 
 GLOBAL(struct jpeg_error_mgr *)
 jpeg_std_error (struct jpeg_error_mgr * err)
 {
   err->error_exit = error_exit;
   err->emit_message = emit_message;
   err->output_message = output_message;
   err->format_message = format_message;
   err->reset_error_mgr = reset_error_mgr;
 
   err->trace_level = 0;		/* default = no tracing */
   err->num_warnings = 0;	/* no warnings emitted yet */
   err->msg_code = 0;		/* may be useful as a flag for "no error" */
 
   /* Initialize message table pointers */
   err->jpeg_message_table = jpeg_std_message_table;
   err->last_jpeg_message = (int) JMSG_LASTMSGCODE - 1;
 
   err->addon_message_table = NULL;
   err->first_addon_message = 0;	/* for safety */
   err->last_addon_message = 0;
 
   return err;
 }