/* | |
* 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 */ | |
/* | |
* 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. | |
*/ | |
const char * const jpeg_std_message_table[] = { | |
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); | |
/* Display it in a message dialog box */ | |
MessageBox(GetActiveWindow(), buffer, "JPEG Library Error", | |
MB_OK | MB_ICONERROR); | |
/* Send it to stderr, adding a newline */ | |
fprintf(stderr, "%s\n", buffer); | |
} | |
/* | |
* 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; | |
} | |