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