1 /*
2  * jerror.c
3  *
4  * Copyright (C) 1991-1998, Thomas G. Lane.
5  * Modified 2012-2015 by Guido Vollbeding.
6  * This file is part of the Independent JPEG Group's software.
7  * For conditions of distribution and use, see the accompanying README file.
8  *
9  * This file contains simple error-reporting and trace-message routines.
10  * These are suitable for Unix-like systems and others where writing to
11  * stderr is the right thing to do.  Many applications will want to replace
12  * some or all of these routines.
13  *
14  * If you define USE_WINDOWS_MESSAGEBOX in jconfig.h or in the makefile,
15  * you get a Windows-specific hack to display error messages in a dialog box.
16  * It ain't much, but it beats dropping error messages into the bit bucket,
17  * which is what happens to output to stderr under most Windows C compilers.
18  *
19  * These routines are used by both the compression and decompression code.
20  */
21 
22 #ifdef USE_WINDOWS_MESSAGEBOX
23 #include <windows.h>
24 #endif
25 
26 /* this is not a core library module, so it doesn't define JPEG_INTERNALS */
27 #include "jinclude.h"
28 #include "jpeglib.h"
29 #include "jversion.h"
30 #include "jerror.h"
31 
32 #ifndef EXIT_FAILURE		/* define exit() codes if not provided */
33 #define EXIT_FAILURE  1
34 #endif
35 
36 
37 /*
38  * Create the message string table.
39  * We do this from the master message list in jerror.h by re-reading
40  * jerror.h with a suitable definition for macro JMESSAGE.
41  * The message table is made an external symbol just in case any applications
42  * want to refer to it directly.
43  */
44 
45 #ifdef NEED_SHORT_EXTERNAL_NAMES
46 #define jpeg_std_message_table	jMsgTable
47 #endif
48 
49 #define JMESSAGE(code,string)	string ,
50 
51 const char * const jpeg_std_message_table[] = {
52 #include "jerror.h"
53   NULL
54 };
55 
56 
57 /*
58  * Error exit handler: must not return to caller.
59  *
60  * Applications may override this if they want to get control back after
61  * an error.  Typically one would longjmp somewhere instead of exiting.
62  * The setjmp buffer can be made a private field within an expanded error
63  * handler object.  Note that the info needed to generate an error message
64  * is stored in the error object, so you can generate the message now or
65  * later, at your convenience.
66  * You should make sure that the JPEG object is cleaned up (with jpeg_abort
67  * or jpeg_destroy) at some point.
68  */
69 
70 METHODDEF(noreturn_t)
error_exit(j_common_ptr cinfo)71 error_exit (j_common_ptr cinfo)
72 {
73   /* Always display the message */
74   (*cinfo->err->output_message) (cinfo);
75 
76   /* Let the memory manager delete any temp files before we die */
77   jpeg_destroy(cinfo);
78 
79   exit(EXIT_FAILURE);
80 }
81 
82 
83 /*
84  * Actual output of an error or trace message.
85  * Applications may override this method to send JPEG messages somewhere
86  * other than stderr.
87  *
88  * On Windows, printing to stderr is generally completely useless,
89  * so we provide optional code to produce an error-dialog popup.
90  * Most Windows applications will still prefer to override this routine,
91  * but if they don't, it'll do something at least marginally useful.
92  *
93  * NOTE: to use the library in an environment that doesn't support the
94  * C stdio library, you may have to delete the call to fprintf() entirely,
95  * not just not use this routine.
96  */
97 
98 METHODDEF(void)
output_message(j_common_ptr cinfo)99 output_message (j_common_ptr cinfo)
100 {
101   char buffer[JMSG_LENGTH_MAX];
102 
103   /* Create the message */
104   (*cinfo->err->format_message) (cinfo, buffer);
105 
106 #ifdef USE_WINDOWS_MESSAGEBOX
107   /* Display it in a message dialog box */
108   MessageBox(GetActiveWindow(), buffer, "JPEG Library Error",
109 	     MB_OK | MB_ICONERROR);
110 #else
111   /* Send it to stderr, adding a newline */
112   fprintf(stderr, "%s\n", buffer);
113 #endif
114 }
115 
116 
117 /*
118  * Decide whether to emit a trace or warning message.
119  * msg_level is one of:
120  *   -1: recoverable corrupt-data warning, may want to abort.
121  *    0: important advisory messages (always display to user).
122  *    1: first level of tracing detail.
123  *    2,3,...: successively more detailed tracing messages.
124  * An application might override this method if it wanted to abort on warnings
125  * or change the policy about which messages to display.
126  */
127 
128 METHODDEF(void)
emit_message(j_common_ptr cinfo,int msg_level)129 emit_message (j_common_ptr cinfo, int msg_level)
130 {
131   struct jpeg_error_mgr * err = cinfo->err;
132 
133   if (msg_level < 0) {
134     /* It's a warning message.  Since corrupt files may generate many warnings,
135      * the policy implemented here is to show only the first warning,
136      * unless trace_level >= 3.
137      */
138     if (err->num_warnings == 0 || err->trace_level >= 3)
139       (*err->output_message) (cinfo);
140     /* Always count warnings in num_warnings. */
141     err->num_warnings++;
142   } else {
143     /* It's a trace message.  Show it if trace_level >= msg_level. */
144     if (err->trace_level >= msg_level)
145       (*err->output_message) (cinfo);
146   }
147 }
148 
149 
150 /*
151  * Format a message string for the most recent JPEG error or message.
152  * The message is stored into buffer, which should be at least JMSG_LENGTH_MAX
153  * characters.  Note that no '\n' character is added to the string.
154  * Few applications should need to override this method.
155  */
156 
157 METHODDEF(void)
format_message(j_common_ptr cinfo,char * buffer)158 format_message (j_common_ptr cinfo, char * buffer)
159 {
160   struct jpeg_error_mgr * err = cinfo->err;
161   int msg_code = err->msg_code;
162   const char * msgtext = NULL;
163   const char * msgptr;
164   char ch;
165   boolean isstring;
166 
167   /* Look up message string in proper table */
168   if (msg_code > 0 && msg_code <= err->last_jpeg_message) {
169     msgtext = err->jpeg_message_table[msg_code];
170   } else if (err->addon_message_table != NULL &&
171 	     msg_code >= err->first_addon_message &&
172 	     msg_code <= err->last_addon_message) {
173     msgtext = err->addon_message_table[msg_code - err->first_addon_message];
174   }
175 
176   /* Defend against bogus message number */
177   if (msgtext == NULL) {
178     err->msg_parm.i[0] = msg_code;
179     msgtext = err->jpeg_message_table[0];
180   }
181 
182   /* Check for string parameter, as indicated by %s in the message text */
183   isstring = FALSE;
184   msgptr = msgtext;
185   while ((ch = *msgptr++) != '\0') {
186     if (ch == '%') {
187       if (*msgptr == 's') isstring = TRUE;
188       break;
189     }
190   }
191 
192   /* Format the message into the passed buffer */
193   if (isstring)
194     sprintf(buffer, msgtext, err->msg_parm.s);
195   else
196     sprintf(buffer, msgtext,
197 	    err->msg_parm.i[0], err->msg_parm.i[1],
198 	    err->msg_parm.i[2], err->msg_parm.i[3],
199 	    err->msg_parm.i[4], err->msg_parm.i[5],
200 	    err->msg_parm.i[6], err->msg_parm.i[7]);
201 }
202 
203 
204 /*
205  * Reset error state variables at start of a new image.
206  * This is called during compression startup to reset trace/error
207  * processing to default state, without losing any application-specific
208  * method pointers.  An application might possibly want to override
209  * this method if it has additional error processing state.
210  */
211 
212 METHODDEF(void)
reset_error_mgr(j_common_ptr cinfo)213 reset_error_mgr (j_common_ptr cinfo)
214 {
215   cinfo->err->num_warnings = 0;
216   /* trace_level is not reset since it is an application-supplied parameter */
217   cinfo->err->msg_code = 0;	/* may be useful as a flag for "no error" */
218 }
219 
220 
221 /*
222  * Fill in the standard error-handling methods in a jpeg_error_mgr object.
223  * Typical call is:
224  *	struct jpeg_compress_struct cinfo;
225  *	struct jpeg_error_mgr err;
226  *
227  *	cinfo.err = jpeg_std_error(&err);
228  * after which the application may override some of the methods.
229  */
230 
231 GLOBAL(struct jpeg_error_mgr *)
jpeg_std_error(struct jpeg_error_mgr * err)232 jpeg_std_error (struct jpeg_error_mgr * err)
233 {
234   err->error_exit = error_exit;
235   err->emit_message = emit_message;
236   err->output_message = output_message;
237   err->format_message = format_message;
238   err->reset_error_mgr = reset_error_mgr;
239 
240   err->trace_level = 0;		/* default = no tracing */
241   err->num_warnings = 0;	/* no warnings emitted yet */
242   err->msg_code = 0;		/* may be useful as a flag for "no error" */
243 
244   /* Initialize message table pointers */
245   err->jpeg_message_table = jpeg_std_message_table;
246   err->last_jpeg_message = (int) JMSG_LASTMSGCODE - 1;
247 
248   err->addon_message_table = NULL;
249   err->first_addon_message = 0;	/* for safety */
250   err->last_addon_message = 0;
251 
252   return err;
253 }
254