/* * 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;}