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