/* * jerror.c * * This file was part of the Independent JPEG Group's software: * Copyright (C) 1991-1998, Thomas G. Lane. * libjpeg-turbo Modifications: * Copyright (C) 2022, D. R. Commander. * For conditions of distribution and use, see the accompanying README.ijg * 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 … #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. */ #define JMESSAGE … const char * const jpeg_std_message_table[] = …; /* * 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) { … } /* * 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) { … } /* * 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) { … } /* * 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) { … } /* * 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) { … } /* * 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) { … }