1 /* 2 * jerror.c 3 * 4 * Copyright (C) 1991-1996, Thomas G. Lane. 5 * This file is part of the Independent JPEG Group's software. 6 * For conditions of distribution and use, see the accompanying README file. 7 * 8 * This file contains simple error-reporting and trace-message routines. 9 * These are suitable for Unix-like systems and others where writing to 10 * stderr is the right thing to do. Many applications will want to replace 11 * some or all of these routines. 12 * 13 * These routines are used by both the compression and decompression code. 14 */ 15 16 /* this is not a core library module, so it doesn't define JPEG_INTERNALS */ 17 #include "jinclude.h" 18 #include "jpeglib.h" 19 #include "jversion.h" 20 #include "jerror.h" 21 22 #ifndef EXIT_FAILURE /* define exit() codes if not provided */ 23 #define EXIT_FAILURE 1 24 #endif 25 26 27 /* 28 * Create the message string table. 29 * We do this from the master message list in jerror.h by re-reading 30 * jerror.h with a suitable definition for macro JMESSAGE. 31 * The message table is made an external symbol just in case any applications 32 * want to refer to it directly. 33 */ 34 35 #ifdef NEED_SHORT_EXTERNAL_NAMES 36 #define jpeg_std_message_table jMsgTable 37 #endif 38 39 #define JMESSAGE(code,string) string , 40 41 const char * const jpeg_std_message_table[] = { 42 #include "jerror.h" 43 NULL 44 }; 45 46 47 /* 48 * Error exit handler: must not return to caller. 49 * 50 * Applications may override this if they want to get control back after 51 * an error. Typically one would longjmp somewhere instead of exiting. 52 * The setjmp buffer can be made a private field within an expanded error 53 * handler object. Note that the info needed to generate an error message 54 * is stored in the error object, so you can generate the message now or 55 * later, at your convenience. 56 * You should make sure that the JPEG object is cleaned up (with jpeg_abort 57 * or jpeg_destroy) at some point. 58 */ 59 60 METHODDEF(void) 61 error_exit (j_common_ptr cinfo) 62 { 63 /* Always display the message */ 64 (*cinfo->err->output_message) (cinfo); 65 66 /* Let the memory manager delete any temp files before we die */ 67 jpeg_destroy(cinfo); 68 69 exit(EXIT_FAILURE); 70 } 71 72 73 /* 74 * Actual output of an error or trace message. 75 * Applications may override this method to send JPEG messages somewhere 76 * other than stderr. 77 */ 78 79 METHODDEF(void) 80 output_message (j_common_ptr cinfo) 81 { 82 char buffer[JMSG_LENGTH_MAX]; 83 84 /* Create the message */ 85 (*cinfo->err->format_message) (cinfo, buffer); 86 87 /* Send it to stderr, adding a newline */ 88 fprintf(stderr, "%s\n", buffer); 89 } 90 91 92 /* 93 * Decide whether to emit a trace or warning message. 94 * msg_level is one of: 95 * -1: recoverable corrupt-data warning, may want to abort. 96 * 0: important advisory messages (always display to user). 97 * 1: first level of tracing detail. 98 * 2,3,...: successively more detailed tracing messages. 99 * An application might override this method if it wanted to abort on warnings 100 * or change the policy about which messages to display. 101 */ 102 103 METHODDEF(void) 104 emit_message (j_common_ptr cinfo, int msg_level) 105 { 106 struct jpeg_error_mgr * err = cinfo->err; 107 108 if (msg_level < 0) { 109 /* It's a warning message. Since corrupt files may generate many warnings, 110 * the policy implemented here is to show only the first warning, 111 * unless trace_level >= 3. 112 */ 113 if (err->num_warnings == 0 || err->trace_level >= 3) 114 (*err->output_message) (cinfo); 115 /* Always count warnings in num_warnings. */ 116 err->num_warnings++; 117 } else { 118 /* It's a trace message. Show it if trace_level >= msg_level. */ 119 if (err->trace_level >= msg_level) 120 (*err->output_message) (cinfo); 121 } 122 } 123 124 125 /* 126 * Format a message string for the most recent JPEG error or message. 127 * The message is stored into buffer, which should be at least JMSG_LENGTH_MAX 128 * characters. Note that no '\n' character is added to the string. 129 * Few applications should need to override this method. 130 */ 131 132 METHODDEF(void) 133 format_message (j_common_ptr cinfo, char * buffer) 134 { 135 struct jpeg_error_mgr * err = cinfo->err; 136 int msg_code = err->msg_code; 137 const char * msgtext = NULL; 138 const char * msgptr; 139 char ch; 140 boolean isstring; 141 142 /* Look up message string in proper table */ 143 if (msg_code > 0 && msg_code <= err->last_jpeg_message) { 144 msgtext = err->jpeg_message_table[msg_code]; 145 } else if (err->addon_message_table != NULL && 146 msg_code >= err->first_addon_message && 147 msg_code <= err->last_addon_message) { 148 msgtext = err->addon_message_table[msg_code - err->first_addon_message]; 149 } 150 151 /* Defend against bogus message number */ 152 if (msgtext == NULL) { 153 err->msg_parm.i[0] = msg_code; 154 msgtext = err->jpeg_message_table[0]; 155 } 156 157 /* Check for string parameter, as indicated by %s in the message text */ 158 isstring = FALSE; 159 msgptr = msgtext; 160 while ((ch = *msgptr++) != '\0') { 161 if (ch == '%') { 162 if (*msgptr == 's') isstring = TRUE; 163 break; 164 } 165 } 166 167 /* Format the message into the passed buffer */ 168 if (isstring) 169 sprintf(buffer, msgtext, err->msg_parm.s); 170 else 171 sprintf(buffer, msgtext, 172 err->msg_parm.i[0], err->msg_parm.i[1], 173 err->msg_parm.i[2], err->msg_parm.i[3], 174 err->msg_parm.i[4], err->msg_parm.i[5], 175 err->msg_parm.i[6], err->msg_parm.i[7]); 176 } 177 178 179 /* 180 * Reset error state variables at start of a new image. 181 * This is called during compression startup to reset trace/error 182 * processing to default state, without losing any application-specific 183 * method pointers. An application might possibly want to override 184 * this method if it has additional error processing state. 185 */ 186 187 METHODDEF(void) 188 reset_error_mgr (j_common_ptr cinfo) 189 { 190 cinfo->err->num_warnings = 0; 191 /* trace_level is not reset since it is an application-supplied parameter */ 192 cinfo->err->msg_code = 0; /* may be useful as a flag for "no error" */ 193 } 194 195 196 /* 197 * Fill in the standard error-handling methods in a jpeg_error_mgr object. 198 * Typical call is: 199 * struct jpeg_compress_struct cinfo; 200 * struct jpeg_error_mgr err; 201 * 202 * cinfo.err = jpeg_std_error(&err); 203 * after which the application may override some of the methods. 204 */ 205 206 GLOBAL(struct jpeg_error_mgr *) 207 jpeg_std_error (struct jpeg_error_mgr * err) 208 { 209 err->error_exit = error_exit; 210 err->emit_message = emit_message; 211 err->output_message = output_message; 212 err->format_message = format_message; 213 err->reset_error_mgr = reset_error_mgr; 214 215 err->trace_level = 0; /* default = no tracing */ 216 err->num_warnings = 0; /* no warnings emitted yet */ 217 err->msg_code = 0; /* may be useful as a flag for "no error" */ 218 219 /* Initialize message table pointers */ 220 err->jpeg_message_table = jpeg_std_message_table; 221 err->last_jpeg_message = (int) JMSG_LASTMSGCODE - 1; 222 223 err->addon_message_table = NULL; 224 err->first_addon_message = 0; /* for safety */ 225 err->last_addon_message = 0; 226 227 return err; 228 } 229