pngerror.c@ 104729

Last change on this file since 104729 was 96425, checked in by vboxsync, 2 years ago
src/libs: Switch to libpng-1.6.37, bugref:8515 [re-export]
Property svn:eol-style set to `native`
File size: 28.5 KB

Line
1
2	/* pngerror.c - stub functions for i/o and memory allocation
3	*
4	* Copyright (c) 2018 Cosmin Truta
5	* Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
6	* Copyright (c) 1996-1997 Andreas Dilger
7	* Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
8	*
9	* This code is released under the libpng license.
10	* For conditions of distribution and use, see the disclaimer
11	* and license in png.h
12	*
13	* This file provides a location for all error handling. Users who
14	* need special error handling are expected to write replacement functions
15	* and use png_set_error_fn() to use those functions. See the instructions
16	* at each function.
17	*/
18
19	#include "pngpriv.h"
20
21	#if defined(PNG_READ_SUPPORTED) \|\| defined(PNG_WRITE_SUPPORTED)
22
23	static PNG_FUNCTION(void, png_default_error,PNGARG((png_const_structrp png_ptr,
24	png_const_charp error_message)),PNG_NORETURN);
25
26	#ifdef PNG_WARNINGS_SUPPORTED
27	static void /* PRIVATE */
28	png_default_warning PNGARG((png_const_structrp png_ptr,
29	png_const_charp warning_message));
30	#endif /* WARNINGS */
31
32	/* This function is called whenever there is a fatal error. This function
33	* should not be changed. If there is a need to handle errors differently,
34	* you should supply a replacement error function and use png_set_error_fn()
35	* to replace the error function at run-time.
36	*/
37	#ifdef PNG_ERROR_TEXT_SUPPORTED
38	PNG_FUNCTION(void,PNGAPI
39	png_error,(png_const_structrp png_ptr, png_const_charp error_message),
40	PNG_NORETURN)
41	{
42	#ifdef PNG_ERROR_NUMBERS_SUPPORTED
43	char msg[16];
44	if (png_ptr != NULL)
45	{
46	if ((png_ptr->flags &
47	(PNG_FLAG_STRIP_ERROR_NUMBERS\|PNG_FLAG_STRIP_ERROR_TEXT)) != 0)
48	{
49	if (*error_message == PNG_LITERAL_SHARP)
50	{
51	/* Strip "#nnnn " from beginning of error message. */
52	int offset;
53	for (offset = 1; offset<15; offset++)
54	if (error_message[offset] == ' ')
55	break;
56
57	if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)
58	{
59	int i;
60	for (i = 0; i < offset - 1; i++)
61	msg[i] = error_message[i + 1];
62	msg[i - 1] = '\0';
63	error_message = msg;
64	}
65
66	else
67	error_message += offset;
68	}
69
70	else
71	{
72	if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)
73	{
74	msg[0] = '0';
75	msg[1] = '\0';
76	error_message = msg;
77	}
78	}
79	}
80	}
81	#endif
82	if (png_ptr != NULL && png_ptr->error_fn != NULL)
83	(*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr),
84	error_message);
85
86	/* If the custom handler doesn't exist, or if it returns,
87	use the default handler, which will not return. */
88	png_default_error(png_ptr, error_message);
89	}
90	#else
91	PNG_FUNCTION(void,PNGAPI
92	png_err,(png_const_structrp png_ptr),PNG_NORETURN)
93	{
94	/* Prior to 1.5.2 the error_fn received a NULL pointer, expressed
95	* erroneously as '\0', instead of the empty string "". This was
96	* apparently an error, introduced in libpng-1.2.20, and png_default_error
97	* will crash in this case.
98	*/
99	if (png_ptr != NULL && png_ptr->error_fn != NULL)
100	(*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), "");
101
102	/* If the custom handler doesn't exist, or if it returns,
103	use the default handler, which will not return. */
104	png_default_error(png_ptr, "");
105	}
106	#endif /* ERROR_TEXT */
107
108	/* Utility to safely appends strings to a buffer. This never errors out so
109	* error checking is not required in the caller.
110	*/
111	size_t
112	png_safecat(png_charp buffer, size_t bufsize, size_t pos,
113	png_const_charp string)
114	{
115	if (buffer != NULL && pos < bufsize)
116	{
117	if (string != NULL)
118	while (*string != '\0' && pos < bufsize-1)
119	buffer[pos++] = *string++;
120
121	buffer[pos] = '\0';
122	}
123
124	return pos;
125	}
126
127	#if defined(PNG_WARNINGS_SUPPORTED) \|\| defined(PNG_TIME_RFC1123_SUPPORTED)
128	/* Utility to dump an unsigned value into a buffer, given a start pointer and
129	* and end pointer (which should point just beyond the end of the buffer!)
130	* Returns the pointer to the start of the formatted string.
131	*/
132	png_charp
133	png_format_number(png_const_charp start, png_charp end, int format,
134	png_alloc_size_t number)
135	{
136	int count = 0; /* number of digits output */
137	int mincount = 1; /* minimum number required */
138	int output = 0; /* digit output (for the fixed point format) */
139
140	*--end = '\0';
141
142	/* This is written so that the loop always runs at least once, even with
143	* number zero.
144	*/
145	while (end > start && (number != 0 \|\| count < mincount))
146	{
147
148	static const char digits[] = "0123456789ABCDEF";
149
150	switch (format)
151	{
152	case PNG_NUMBER_FORMAT_fixed:
153	/* Needs five digits (the fraction) */
154	mincount = 5;
155	if (output != 0 \|\| number % 10 != 0)
156	{
157	*--end = digits[number % 10];
158	output = 1;
159	}
160	number /= 10;
161	break;
162
163	case PNG_NUMBER_FORMAT_02u:
164	/* Expects at least 2 digits. */
165	mincount = 2;
166	/* FALLTHROUGH */
167
168	case PNG_NUMBER_FORMAT_u:
169	*--end = digits[number % 10];
170	number /= 10;
171	break;
172
173	case PNG_NUMBER_FORMAT_02x:
174	/* This format expects at least two digits */
175	mincount = 2;
176	/* FALLTHROUGH */
177
178	case PNG_NUMBER_FORMAT_x:
179	*--end = digits[number & 0xf];
180	number >>= 4;
181	break;
182
183	default: /* an error */
184	number = 0;
185	break;
186	}
187
188	/* Keep track of the number of digits added */
189	++count;
190
191	/* Float a fixed number here: */
192	if ((format == PNG_NUMBER_FORMAT_fixed) && (count == 5) && (end > start))
193	{
194	/* End of the fraction, but maybe nothing was output? In that case
195	* drop the decimal point. If the number is a true zero handle that
196	* here.
197	*/
198	if (output != 0)
199	*--end = '.';
200	else if (number == 0) /* and !output */
201	*--end = '0';
202	}
203	}
204
205	return end;
206	}
207	#endif
208
209	#ifdef PNG_WARNINGS_SUPPORTED
210	/* This function is called whenever there is a non-fatal error. This function
211	* should not be changed. If there is a need to handle warnings differently,
212	* you should supply a replacement warning function and use
213	* png_set_error_fn() to replace the warning function at run-time.
214	*/
215	void PNGAPI
216	png_warning(png_const_structrp png_ptr, png_const_charp warning_message)
217	{
218	int offset = 0;
219	if (png_ptr != NULL)
220	{
221	#ifdef PNG_ERROR_NUMBERS_SUPPORTED
222	if ((png_ptr->flags &
223	(PNG_FLAG_STRIP_ERROR_NUMBERS\|PNG_FLAG_STRIP_ERROR_TEXT)) != 0)
224	#endif
225	{
226	if (*warning_message == PNG_LITERAL_SHARP)
227	{
228	for (offset = 1; offset < 15; offset++)
229	if (warning_message[offset] == ' ')
230	break;
231	}
232	}
233	}
234	if (png_ptr != NULL && png_ptr->warning_fn != NULL)
235	(*(png_ptr->warning_fn))(png_constcast(png_structrp,png_ptr),
236	warning_message + offset);
237	else
238	png_default_warning(png_ptr, warning_message + offset);
239	}
240
241	/* These functions support 'formatted' warning messages with up to
242	* PNG_WARNING_PARAMETER_COUNT parameters. In the format string the parameter
243	* is introduced by @<number>, where 'number' starts at 1. This follows the
244	* standard established by X/Open for internationalizable error messages.
245	*/
246	void
247	png_warning_parameter(png_warning_parameters p, int number,
248	png_const_charp string)
249	{
250	if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT)
251	(void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string);
252	}
253
254	void
255	png_warning_parameter_unsigned(png_warning_parameters p, int number, int format,
256	png_alloc_size_t value)
257	{
258	char buffer[PNG_NUMBER_BUFFER_SIZE];
259	png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value));
260	}
261
262	void
263	png_warning_parameter_signed(png_warning_parameters p, int number, int format,
264	png_int_32 value)
265	{
266	png_alloc_size_t u;
267	png_charp str;
268	char buffer[PNG_NUMBER_BUFFER_SIZE];
269
270	/* Avoid overflow by doing the negate in a png_alloc_size_t: */
271	u = (png_alloc_size_t)value;
272	if (value < 0)
273	u = ~u + 1;
274
275	str = PNG_FORMAT_NUMBER(buffer, format, u);
276
277	if (value < 0 && str > buffer)
278	*--str = '-';
279
280	png_warning_parameter(p, number, str);
281	}
282
283	void
284	png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p,
285	png_const_charp message)
286	{
287	/* The internal buffer is just 192 bytes - enough for all our messages,
288	* overflow doesn't happen because this code checks! If someone figures
289	* out how to send us a message longer than 192 bytes, all that will
290	* happen is that the message will be truncated appropriately.
291	*/
292	size_t i = 0; /* Index in the msg[] buffer: */
293	char msg[192];
294
295	/* Each iteration through the following loop writes at most one character
296	* to msg[i++] then returns here to validate that there is still space for
297	* the trailing '\0'. It may (in the case of a parameter) read more than
298	* one character from message[]; it must check for '\0' and continue to the
299	* test if it finds the end of string.
300	*/
301	while (i<(sizeof msg)-1 && *message != '\0')
302	{
303	/* '@' at end of string is now just printed (previously it was skipped);
304	* it is an error in the calling code to terminate the string with @.
305	*/
306	if (p != NULL && *message == '@' && message[1] != '\0')
307	{
308	int parameter_char = ++message; / Consume the '@' */
309	static const char valid_parameters[] = "123456789";
310	int parameter = 0;
311
312	/* Search for the parameter digit, the index in the string is the
313	* parameter to use.
314	*/
315	while (valid_parameters[parameter] != parameter_char &&
316	valid_parameters[parameter] != '\0')
317	++parameter;
318
319	/* If the parameter digit is out of range it will just get printed. */
320	if (parameter < PNG_WARNING_PARAMETER_COUNT)
321	{
322	/* Append this parameter */
323	png_const_charp parm = p[parameter];
324	png_const_charp pend = p[parameter] + (sizeof p[parameter]);
325
326	/* No need to copy the trailing '\0' here, but there is no guarantee
327	* that parm[] has been initialized, so there is no guarantee of a
328	* trailing '\0':
329	*/
330	while (i<(sizeof msg)-1 && *parm != '\0' && parm < pend)
331	msg[i++] = *parm++;
332
333	/* Consume the parameter digit too: */
334	++message;
335	continue;
336	}
337
338	/* else not a parameter and there is a character after the @ sign; just
339	* copy that. This is known not to be '\0' because of the test above.
340	*/
341	}
342
343	/* At this point *message can't be '\0', even in the bad parameter case
344	* above where there is a lone '@' at the end of the message string.
345	*/
346	msg[i++] = *message++;
347	}
348
349	/* i is always less than (sizeof msg), so: */
350	msg[i] = '\0';
351
352	/* And this is the formatted message. It may be larger than
353	* PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these
354	* are not (currently) formatted.
355	*/
356	png_warning(png_ptr, msg);
357	}
358	#endif /* WARNINGS */
359
360	#ifdef PNG_BENIGN_ERRORS_SUPPORTED
361	void PNGAPI
362	png_benign_error(png_const_structrp png_ptr, png_const_charp error_message)
363	{
364	if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0)
365	{
366	# ifdef PNG_READ_SUPPORTED
367	if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
368	png_ptr->chunk_name != 0)
369	png_chunk_warning(png_ptr, error_message);
370	else
371	# endif
372	png_warning(png_ptr, error_message);
373	}
374
375	else
376	{
377	# ifdef PNG_READ_SUPPORTED
378	if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
379	png_ptr->chunk_name != 0)
380	png_chunk_error(png_ptr, error_message);
381	else
382	# endif
383	png_error(png_ptr, error_message);
384	}
385
386	# ifndef PNG_ERROR_TEXT_SUPPORTED
387	PNG_UNUSED(error_message)
388	# endif
389	}
390
391	void /* PRIVATE */
392	png_app_warning(png_const_structrp png_ptr, png_const_charp error_message)
393	{
394	if ((png_ptr->flags & PNG_FLAG_APP_WARNINGS_WARN) != 0)
395	png_warning(png_ptr, error_message);
396	else
397	png_error(png_ptr, error_message);
398
399	# ifndef PNG_ERROR_TEXT_SUPPORTED
400	PNG_UNUSED(error_message)
401	# endif
402	}
403
404	void /* PRIVATE */
405	png_app_error(png_const_structrp png_ptr, png_const_charp error_message)
406	{
407	if ((png_ptr->flags & PNG_FLAG_APP_ERRORS_WARN) != 0)
408	png_warning(png_ptr, error_message);
409	else
410	png_error(png_ptr, error_message);
411
412	# ifndef PNG_ERROR_TEXT_SUPPORTED
413	PNG_UNUSED(error_message)
414	# endif
415	}
416	#endif /* BENIGN_ERRORS */
417
418	#define PNG_MAX_ERROR_TEXT 196 /* Currently limited by profile_error in png.c */
419	#if defined(PNG_WARNINGS_SUPPORTED) \|\| \
420	(defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED))
421	/* These utilities are used internally to build an error message that relates
422	* to the current chunk. The chunk name comes from png_ptr->chunk_name,
423	* which is used to prefix the message. The message is limited in length
424	* to 63 bytes. The name characters are output as hex digits wrapped in []
425	* if the character is invalid.
426	*/
427	#define isnonalpha(c) ((c) < 65 \|\| (c) > 122 \|\| ((c) > 90 && (c) < 97))
428	static const char png_digit[16] = {
429	'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
430	'A', 'B', 'C', 'D', 'E', 'F'
431	};
432
433	static void /* PRIVATE */
434	png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp
435	error_message)
436	{
437	png_uint_32 chunk_name = png_ptr->chunk_name;
438	int iout = 0, ishift = 24;
439
440	while (ishift >= 0)
441	{
442	int c = (int)(chunk_name >> ishift) & 0xff;
443
444	ishift -= 8;
445	if (isnonalpha(c) != 0)
446	{
447	buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET;
448	buffer[iout++] = png_digit[(c & 0xf0) >> 4];
449	buffer[iout++] = png_digit[c & 0x0f];
450	buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET;
451	}
452
453	else
454	{
455	buffer[iout++] = (char)c;
456	}
457	}
458
459	if (error_message == NULL)
460	buffer[iout] = '\0';
461
462	else
463	{
464	int iin = 0;
465
466	buffer[iout++] = ':';
467	buffer[iout++] = ' ';
468
469	while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0')
470	buffer[iout++] = error_message[iin++];
471
472	/* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */
473	buffer[iout] = '\0';
474	}
475	}
476	#endif /* WARNINGS \|\| ERROR_TEXT */
477
478	#if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
479	PNG_FUNCTION(void,PNGAPI
480	png_chunk_error,(png_const_structrp png_ptr, png_const_charp error_message),
481	PNG_NORETURN)
482	{
483	char msg[18+PNG_MAX_ERROR_TEXT];
484	if (png_ptr == NULL)
485	png_error(png_ptr, error_message);
486
487	else
488	{
489	png_format_buffer(png_ptr, msg, error_message);
490	png_error(png_ptr, msg);
491	}
492	}
493	#endif /* READ && ERROR_TEXT */
494
495	#ifdef PNG_WARNINGS_SUPPORTED
496	void PNGAPI
497	png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message)
498	{
499	char msg[18+PNG_MAX_ERROR_TEXT];
500	if (png_ptr == NULL)
501	png_warning(png_ptr, warning_message);
502
503	else
504	{
505	png_format_buffer(png_ptr, msg, warning_message);
506	png_warning(png_ptr, msg);
507	}
508	}
509	#endif /* WARNINGS */
510
511	#ifdef PNG_READ_SUPPORTED
512	#ifdef PNG_BENIGN_ERRORS_SUPPORTED
513	void PNGAPI
514	png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp
515	error_message)
516	{
517	if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0)
518	png_chunk_warning(png_ptr, error_message);
519
520	else
521	png_chunk_error(png_ptr, error_message);
522
523	# ifndef PNG_ERROR_TEXT_SUPPORTED
524	PNG_UNUSED(error_message)
525	# endif
526	}
527	#endif
528	#endif /* READ */
529
530	void /* PRIVATE */
531	png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error)
532	{
533	# ifndef PNG_WARNINGS_SUPPORTED
534	PNG_UNUSED(message)
535	# endif
536
537	/* This is always supported, but for just read or just write it
538	* unconditionally does the right thing.
539	*/
540	# if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
541	if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
542	# endif
543
544	# ifdef PNG_READ_SUPPORTED
545	{
546	if (error < PNG_CHUNK_ERROR)
547	png_chunk_warning(png_ptr, message);
548
549	else
550	png_chunk_benign_error(png_ptr, message);
551	}
552	# endif
553
554	# if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
555	else if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
556	# endif
557
558	# ifdef PNG_WRITE_SUPPORTED
559	{
560	if (error < PNG_CHUNK_WRITE_ERROR)
561	png_app_warning(png_ptr, message);
562
563	else
564	png_app_error(png_ptr, message);
565	}
566	# endif
567	}
568
569	#ifdef PNG_ERROR_TEXT_SUPPORTED
570	#ifdef PNG_FLOATING_POINT_SUPPORTED
571	PNG_FUNCTION(void,
572	png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN)
573	{
574	# define fixed_message "fixed point overflow in "
575	# define fixed_message_ln ((sizeof fixed_message)-1)
576	unsigned int iin;
577	char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT];
578	memcpy(msg, fixed_message, fixed_message_ln);
579	iin = 0;
580	if (name != NULL)
581	while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0)
582	{
583	msg[fixed_message_ln + iin] = name[iin];
584	++iin;
585	}
586	msg[fixed_message_ln + iin] = 0;
587	png_error(png_ptr, msg);
588	}
589	#endif
590	#endif
591
592	#ifdef PNG_SETJMP_SUPPORTED
593	/* This API only exists if ANSI-C style error handling is used,
594	* otherwise it is necessary for png_default_error to be overridden.
595	*/
596	jmp_buf* PNGAPI
597	png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn,
598	size_t jmp_buf_size)
599	{
600	/* From libpng 1.6.0 the app gets one chance to set a 'jmpbuf_size' value
601	* and it must not change after that. Libpng doesn't care how big the
602	* buffer is, just that it doesn't change.
603	*
604	* If the buffer size is no larger than the size of jmp_buf when libpng is
605	* compiled a built in jmp_buf is returned; this preserves the pre-1.6.0
606	* semantics that this call will not fail. If the size is larger, however,
607	* the buffer is allocated and this may fail, causing the function to return
608	* NULL.
609	*/
610	if (png_ptr == NULL)
611	return NULL;
612
613	if (png_ptr->jmp_buf_ptr == NULL)
614	{
615	png_ptr->jmp_buf_size = 0; /* not allocated */
616
617	if (jmp_buf_size <= (sizeof png_ptr->jmp_buf_local))
618	png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local;
619
620	else
621	{
622	png_ptr->jmp_buf_ptr = png_voidcast(jmp_buf *,
623	png_malloc_warn(png_ptr, jmp_buf_size));
624
625	if (png_ptr->jmp_buf_ptr == NULL)
626	return NULL; /* new NULL return on OOM */
627
628	png_ptr->jmp_buf_size = jmp_buf_size;
629	}
630	}
631
632	else /* Already allocated: check the size */
633	{
634	size_t size = png_ptr->jmp_buf_size;
635
636	if (size == 0)
637	{
638	size = (sizeof png_ptr->jmp_buf_local);
639	if (png_ptr->jmp_buf_ptr != &png_ptr->jmp_buf_local)
640	{
641	/* This is an internal error in libpng: somehow we have been left
642	* with a stack allocated jmp_buf when the application regained
643	* control. It's always possible to fix this up, but for the moment
644	* this is a png_error because that makes it easy to detect.
645	*/
646	png_error(png_ptr, "Libpng jmp_buf still allocated");
647	/* png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; */
648	}
649	}
650
651	if (size != jmp_buf_size)
652	{
653	png_warning(png_ptr, "Application jmp_buf size changed");
654	return NULL; /* caller will probably crash: no choice here */
655	}
656	}
657
658	/* Finally fill in the function, now we have a satisfactory buffer. It is
659	* valid to change the function on every call.
660	*/
661	png_ptr->longjmp_fn = longjmp_fn;
662	return png_ptr->jmp_buf_ptr;
663	}
664
665	void /* PRIVATE */
666	png_free_jmpbuf(png_structrp png_ptr)
667	{
668	if (png_ptr != NULL)
669	{
670	jmp_buf *jb = png_ptr->jmp_buf_ptr;
671
672	/* A size of 0 is used to indicate a local, stack, allocation of the
673	* pointer; used here and in png.c
674	*/
675	if (jb != NULL && png_ptr->jmp_buf_size > 0)
676	{
677
678	/* This stuff is so that a failure to free the error control structure
679	* does not leave libpng in a state with no valid error handling: the
680	* free always succeeds, if there is an error it gets ignored.
681	*/
682	if (jb != &png_ptr->jmp_buf_local)
683	{
684	/* Make an internal, libpng, jmp_buf to return here */
685	jmp_buf free_jmp_buf;
686
687	if (!setjmp(free_jmp_buf))
688	{
689	png_ptr->jmp_buf_ptr = &free_jmp_buf; /* come back here */
690	png_ptr->jmp_buf_size = 0; /* stack allocation */
691	png_ptr->longjmp_fn = longjmp;
692	png_free(png_ptr, jb); /* Return to setjmp on error */
693	}
694	}
695	}
696
697	/* Always cancel everything out: */
698	png_ptr->jmp_buf_size = 0;
699	png_ptr->jmp_buf_ptr = NULL;
700	png_ptr->longjmp_fn = 0;
701	}
702	}
703	#endif
704
705	/* This is the default error handling function. Note that replacements for
706	* this function MUST NOT RETURN, or the program will likely crash. This
707	* function is used by default, or if the program supplies NULL for the
708	* error function pointer in png_set_error_fn().
709	*/
710	static PNG_FUNCTION(void /* PRIVATE */,
711	png_default_error,(png_const_structrp png_ptr, png_const_charp error_message),
712	PNG_NORETURN)
713	{
714	#ifdef PNG_CONSOLE_IO_SUPPORTED
715	#ifdef PNG_ERROR_NUMBERS_SUPPORTED
716	/* Check on NULL only added in 1.5.4 */
717	if (error_message != NULL && *error_message == PNG_LITERAL_SHARP)
718	{
719	/* Strip "#nnnn " from beginning of error message. */
720	int offset;
721	char error_number[16];
722	for (offset = 0; offset<15; offset++)
723	{
724	error_number[offset] = error_message[offset + 1];
725	if (error_message[offset] == ' ')
726	break;
727	}
728
729	if ((offset > 1) && (offset < 15))
730	{
731	error_number[offset - 1] = '\0';
732	fprintf(stderr, "libpng error no. %s: %s",
733	error_number, error_message + offset + 1);
734	fprintf(stderr, PNG_STRING_NEWLINE);
735	}
736
737	else
738	{
739	fprintf(stderr, "libpng error: %s, offset=%d",
740	error_message, offset);
741	fprintf(stderr, PNG_STRING_NEWLINE);
742	}
743	}
744	else
745	#endif
746	{
747	fprintf(stderr, "libpng error: %s", error_message ? error_message :
748	"undefined");
749	fprintf(stderr, PNG_STRING_NEWLINE);
750	}
751	#else
752	PNG_UNUSED(error_message) /* Make compiler happy */
753	#endif
754	png_longjmp(png_ptr, 1);
755	}
756
757	PNG_FUNCTION(void,PNGAPI
758	png_longjmp,(png_const_structrp png_ptr, int val),PNG_NORETURN)
759	{
760	#ifdef PNG_SETJMP_SUPPORTED
761	if (png_ptr != NULL && png_ptr->longjmp_fn != NULL &&
762	png_ptr->jmp_buf_ptr != NULL)
763	png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val);
764	#else
765	PNG_UNUSED(png_ptr)
766	PNG_UNUSED(val)
767	#endif
768
769	/* If control reaches this point, png_longjmp() must not return. The only
770	* choice is to terminate the whole process (or maybe the thread); to do
771	* this the ANSI-C abort() function is used unless a different method is
772	* implemented by overriding the default configuration setting for
773	* PNG_ABORT().
774	*/
775	PNG_ABORT();
776	}
777
778	#ifdef PNG_WARNINGS_SUPPORTED
779	/* This function is called when there is a warning, but the library thinks
780	* it can continue anyway. Replacement functions don't have to do anything
781	* here if you don't want them to. In the default configuration, png_ptr is
782	* not used, but it is passed in case it may be useful.
783	*/
784	static void /* PRIVATE */
785	png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message)
786	{
787	#ifdef PNG_CONSOLE_IO_SUPPORTED
788	# ifdef PNG_ERROR_NUMBERS_SUPPORTED
789	if (*warning_message == PNG_LITERAL_SHARP)
790	{
791	int offset;
792	char warning_number[16];
793	for (offset = 0; offset < 15; offset++)
794	{
795	warning_number[offset] = warning_message[offset + 1];
796	if (warning_message[offset] == ' ')
797	break;
798	}
799
800	if ((offset > 1) && (offset < 15))
801	{
802	warning_number[offset + 1] = '\0';
803	fprintf(stderr, "libpng warning no. %s: %s",
804	warning_number, warning_message + offset);
805	fprintf(stderr, PNG_STRING_NEWLINE);
806	}
807
808	else
809	{
810	fprintf(stderr, "libpng warning: %s",
811	warning_message);
812	fprintf(stderr, PNG_STRING_NEWLINE);
813	}
814	}
815	else
816	# endif
817
818	{
819	fprintf(stderr, "libpng warning: %s", warning_message);
820	fprintf(stderr, PNG_STRING_NEWLINE);
821	}
822	#else
823	PNG_UNUSED(warning_message) /* Make compiler happy */
824	#endif
825	PNG_UNUSED(png_ptr) /* Make compiler happy */
826	}
827	#endif /* WARNINGS */
828
829	/* This function is called when the application wants to use another method
830	* of handling errors and warnings. Note that the error function MUST NOT
831	* return to the calling routine or serious problems will occur. The return
832	* method used in the default routine calls longjmp(png_ptr->jmp_buf_ptr, 1)
833	*/
834	void PNGAPI
835	png_set_error_fn(png_structrp png_ptr, png_voidp error_ptr,
836	png_error_ptr error_fn, png_error_ptr warning_fn)
837	{
838	if (png_ptr == NULL)
839	return;
840
841	png_ptr->error_ptr = error_ptr;
842	png_ptr->error_fn = error_fn;
843	#ifdef PNG_WARNINGS_SUPPORTED
844	png_ptr->warning_fn = warning_fn;
845	#else
846	PNG_UNUSED(warning_fn)
847	#endif
848	}
849
850
851	/* This function returns a pointer to the error_ptr associated with the user
852	* functions. The application should free any memory associated with this
853	* pointer before png_write_destroy and png_read_destroy are called.
854	*/
855	png_voidp PNGAPI
856	png_get_error_ptr(png_const_structrp png_ptr)
857	{
858	if (png_ptr == NULL)
859	return NULL;
860
861	return ((png_voidp)png_ptr->error_ptr);
862	}
863
864
865	#ifdef PNG_ERROR_NUMBERS_SUPPORTED
866	void PNGAPI
867	png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode)
868	{
869	if (png_ptr != NULL)
870	{
871	png_ptr->flags &=
872	((~(PNG_FLAG_STRIP_ERROR_NUMBERS \|
873	PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
874	}
875	}
876	#endif
877
878	#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) \|\|\
879	defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
880	/* Currently the above both depend on SETJMP_SUPPORTED, however it would be
881	* possible to implement without setjmp support just so long as there is some
882	* way to handle the error return here:
883	*/
884	PNG_FUNCTION(void /* PRIVATE */, (PNGCBAPI
885	png_safe_error),(png_structp png_nonconst_ptr, png_const_charp error_message),
886	PNG_NORETURN)
887	{
888	png_const_structrp png_ptr = png_nonconst_ptr;
889	png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
890
891	/* An error is always logged here, overwriting anything (typically a warning)
892	* that is already there:
893	*/
894	if (image != NULL)
895	{
896	png_safecat(image->message, (sizeof image->message), 0, error_message);
897	image->warning_or_error \|= PNG_IMAGE_ERROR;
898
899	/* Retrieve the jmp_buf from within the png_control, making this work for
900	* C++ compilation too is pretty tricky: C++ wants a pointer to the first
901	* element of a jmp_buf, but C doesn't tell us the type of that.
902	*/
903	if (image->opaque != NULL && image->opaque->error_buf != NULL)
904	longjmp(png_control_jmp_buf(image->opaque), 1);
905
906	/* Missing longjmp buffer, the following is to help debugging: */
907	{
908	size_t pos = png_safecat(image->message, (sizeof image->message), 0,
909	"bad longjmp: ");
910	png_safecat(image->message, (sizeof image->message), pos,
911	error_message);
912	}
913	}
914
915	/* Here on an internal programming error. */
916	abort();
917	}
918
919	#ifdef PNG_WARNINGS_SUPPORTED
920	void /* PRIVATE */ PNGCBAPI
921	png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message)
922	{
923	png_const_structrp png_ptr = png_nonconst_ptr;
924	png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
925
926	/* A warning is only logged if there is no prior warning or error. */
927	if (image->warning_or_error == 0)
928	{
929	png_safecat(image->message, (sizeof image->message), 0, warning_message);
930	image->warning_or_error \|= PNG_IMAGE_WARNING;
931	}
932	}
933	#endif
934
935	int /* PRIVATE */
936	png_safe_execute(png_imagep image_in, int (*function)(png_voidp), png_voidp arg)
937	{
938	volatile png_imagep image = image_in;
939	volatile int result;
940	volatile png_voidp saved_error_buf;
941	jmp_buf safe_jmpbuf;
942
943	/* Safely execute function(arg) with png_error returning to this function. */
944	saved_error_buf = image->opaque->error_buf;
945	result = setjmp(safe_jmpbuf) == 0;
946
947	if (result != 0)
948	{
949
950	image->opaque->error_buf = safe_jmpbuf;
951	result = function(arg);
952	}
953
954	image->opaque->error_buf = saved_error_buf;
955
956	/* And do the cleanup prior to any failure return. */
957	if (result == 0)
958	png_image_free(image);
959
960	return result;
961	}
962	#endif /* SIMPLIFIED READ \|\| SIMPLIFIED_WRITE */
963	#endif /* READ \|\| WRITE */

Note: See TracBrowser for help on using the repository browser.

source: vbox/trunk/src/libs/libpng-1.6.37/pngerror.c@ 104729

Download in other formats: