cheng/libpng
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
f8dfd123e2
libpng/pngerror.c
John Bowler f8dfd123e2 [libpng16] Changed ICC profile support to allow use of an external color 
management system (CMS). In practice it is not possible to obtain cHRM
information reliably using just the end-point tags because they do not exist
in the vast majority of profiles.  Instead it is necessary to run the endpoints
through the ICC colorimetric intent transform (as described in the v4
spec).  Since this is likely to be too much code inside libpng for too
little gain (it implies a fairly complete CMS implementation) the code
has been changed to allow an external CMS to be used.  This code is
temporarily disabled until a suitable set of test cases using one or more
external CMS implementations have been implemented.
2012-10-25 19:30:02 -05:00

933 lines
28 KiB
C
Raw Blame History

/* pngerror.c - stub functions for i/o and memory allocation
*
* Last changed in libpng 1.6.0 [(PENDING RELEASE)]
* Copyright (c) 1998-2012 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
* and license in png.h
*
* This file provides a location for all error handling. Users who
* need special error handling are expected to write replacement functions
* and use png_set_error_fn() to use those functions. See the instructions
* at each function.
*/
#include "pngpriv.h"
#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
static PNG_FUNCTION(void, png_default_error,PNGARG((png_const_structrp png_ptr,
png_const_charp error_message)),PNG_NORETURN);
#ifdef PNG_WARNINGS_SUPPORTED
static void /* PRIVATE */
png_default_warning PNGARG((png_const_structrp png_ptr,
png_const_charp warning_message));
#endif /* PNG_WARNINGS_SUPPORTED */
/* This function is called whenever there is a fatal error. This function
* should not be changed. If there is a need to handle errors differently,
* you should supply a replacement error function and use png_set_error_fn()
* to replace the error function at run-time.
*/
#ifdef PNG_ERROR_TEXT_SUPPORTED
PNG_FUNCTION(void,PNGAPI
png_error,(png_const_structrp png_ptr, png_const_charp error_message),
PNG_NORETURN)
{
#ifdef PNG_ERROR_NUMBERS_SUPPORTED
char msg[16];
if (png_ptr != NULL)
{
if (png_ptr->flags&
(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
{
if (*error_message == PNG_LITERAL_SHARP)
{
/* Strip "#nnnn " from beginning of error message. */
int offset;
for (offset = 1; offset<15; offset++)
if (error_message[offset] == ' ')
break;
if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
{
int i;
for (i = 0; i < offset - 1; i++)
msg[i] = error_message[i + 1];
msg[i - 1] = '\0';
error_message = msg;
}
else
error_message += offset;
}
else
{
if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
{
msg[0] = '0';
msg[1] = '\0';
error_message = msg;
}
}
}
}
#endif
if (png_ptr != NULL && png_ptr->error_fn != NULL)
(*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr),
error_message);
/* If the custom handler doesn't exist, or if it returns,
use the default handler, which will not return. */
png_default_error(png_ptr, error_message);
}
#else
PNG_FUNCTION(void,PNGAPI
png_err,(png_const_structrp png_ptr),PNG_NORETURN)
{
/* Prior to 1.5.2 the error_fn received a NULL pointer, expressed
* erroneously as '\0', instead of the empty string "". This was
* apparently an error, introduced in libpng-1.2.20, and png_default_error
* will crash in this case.
*/
if (png_ptr != NULL && png_ptr->error_fn != NULL)
(*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), "");
/* If the custom handler doesn't exist, or if it returns,
use the default handler, which will not return. */
png_default_error(png_ptr, "");
}
#endif /* PNG_ERROR_TEXT_SUPPORTED */
/* Utility to safely appends strings to a buffer. This never errors out so
* error checking is not required in the caller.
*/
size_t
png_safecat(png_charp buffer, size_t bufsize, size_t pos,
png_const_charp string)
{
if (buffer != NULL && pos < bufsize)
{
if (string != NULL)
while (*string != '\0' && pos < bufsize-1)
buffer[pos++] = *string++;
buffer[pos] = '\0';
}
return pos;
}
#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
/* Utility to dump an unsigned value into a buffer, given a start pointer and
* and end pointer (which should point just *beyond* the end of the buffer!)
* Returns the pointer to the start of the formatted string.
*/
png_charp
png_format_number(png_const_charp start, png_charp end, int format,
png_alloc_size_t number)
{
int count = 0; /* number of digits output */
int mincount = 1; /* minimum number required */
int output = 0; /* digit output (for the fixed point format) */
*--end = '\0';
/* This is written so that the loop always runs at least once, even with
* number zero.
*/
while (end > start && (number != 0 || count < mincount))
{
static const char digits[] = "0123456789ABCDEF";
switch (format)
{
case PNG_NUMBER_FORMAT_fixed:
/* Needs five digits (the fraction) */
mincount = 5;
if (output || number % 10 != 0)
{
*--end = digits[number % 10];
output = 1;
}
number /= 10;
break;
case PNG_NUMBER_FORMAT_02u:
/* Expects at least 2 digits. */
mincount = 2;
/* fall through */
case PNG_NUMBER_FORMAT_u:
*--end = digits[number % 10];
number /= 10;
break;
case PNG_NUMBER_FORMAT_02x:
/* This format expects at least two digits */
mincount = 2;
/* fall through */
case PNG_NUMBER_FORMAT_x:
*--end = digits[number & 0xf];
number >>= 4;
break;
default: /* an error */
number = 0;
break;
}
/* Keep track of the number of digits added */
++count;
/* Float a fixed number here: */
if (format == PNG_NUMBER_FORMAT_fixed) if (count == 5) if (end > start)
{
/* End of the fraction, but maybe nothing was output? In that case
* drop the decimal point. If the number is a true zero handle that
* here.
*/
if (output)
*--end = '.';
else if (number == 0) /* and !output */
*--end = '0';
}
}
return end;
}
#endif
#ifdef PNG_WARNINGS_SUPPORTED
/* This function is called whenever there is a non-fatal error. This function
* should not be changed. If there is a need to handle warnings differently,
* you should supply a replacement warning function and use
* png_set_error_fn() to replace the warning function at run-time.
*/
void PNGAPI
png_warning(png_const_structrp png_ptr, png_const_charp warning_message)
{
int offset = 0;
if (png_ptr != NULL)
{
#ifdef PNG_ERROR_NUMBERS_SUPPORTED
if (png_ptr->flags&
(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
#endif
{
if (*warning_message == PNG_LITERAL_SHARP)
{
for (offset = 1; offset < 15; offset++)
if (warning_message[offset] == ' ')
break;
}
}
}
if (png_ptr != NULL && png_ptr->warning_fn != NULL)
(*(png_ptr->warning_fn))(png_constcast(png_structrp,png_ptr),
warning_message + offset);
else
png_default_warning(png_ptr, warning_message + offset);
}
/* These functions support 'formatted' warning messages with up to
* PNG_WARNING_PARAMETER_COUNT parameters. In the format string the parameter
* is introduced by @<number>, where 'number' starts at 1. This follows the
* standard established by X/Open for internationalizable error messages.
*/
void
png_warning_parameter(png_warning_parameters p, int number,
png_const_charp string)
{
if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT)
(void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string);
}
void
png_warning_parameter_unsigned(png_warning_parameters p, int number, int format,
png_alloc_size_t value)
{
char buffer[PNG_NUMBER_BUFFER_SIZE];
png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value));
}
void
png_warning_parameter_signed(png_warning_parameters p, int number, int format,
png_int_32 value)
{
png_alloc_size_t u;
png_charp str;
char buffer[PNG_NUMBER_BUFFER_SIZE];
/* Avoid overflow by doing the negate in a png_alloc_size_t: */
u = (png_alloc_size_t)value;
if (value < 0)
u = ~u + 1;
str = PNG_FORMAT_NUMBER(buffer, format, u);
if (value < 0 && str > buffer)
*--str = '-';
png_warning_parameter(p, number, str);
}
void
png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p,
png_const_charp message)
{
/* The internal buffer is just 192 bytes - enough for all our messages,
* overflow doesn't happen because this code checks! If someone figures
* out how to send us a message longer than 192 bytes, all that will
* happen is that the message will be truncated appropriately.
*/
size_t i = 0; /* Index in the msg[] buffer: */
char msg[192];
/* Each iteration through the following loop writes at most one character
* to msg[i++] then returns here to validate that there is still space for
* the trailing '\0'. It may (in the case of a parameter) read more than
* one character from message[]; it must check for '\0' and continue to the
* test if it finds the end of string.
*/
while (i<(sizeof msg)-1 && *message != '\0')
{
/* '@' at end of string is now just printed (previously it was skipped);
* it is an error in the calling code to terminate the string with @.
*/
if (p != NULL && *message == '@' && message[1] != '\0')
{
int parameter_char = *++message; /* Consume the '@' */
static const char valid_parameters[] = "123456789";
int parameter = 0;
/* Search for the parameter digit, the index in the string is the
* parameter to use.
*/
while (valid_parameters[parameter] != parameter_char &&
valid_parameters[parameter] != '\0')
++parameter;
/* If the parameter digit is out of range it will just get printed. */
if (parameter < PNG_WARNING_PARAMETER_COUNT)
{
/* Append this parameter */
png_const_charp parm = p[parameter];
png_const_charp pend = p[parameter] + (sizeof p[parameter]);
/* No need to copy the trailing '\0' here, but there is no guarantee
* that parm[] has been initialized, so there is no guarantee of a
* trailing '\0':
*/
while (i<(sizeof msg)-1 && *parm != '\0' && parm < pend)
msg[i++] = *parm++;
/* Consume the parameter digit too: */
++message;
continue;
}
/* else not a parameter and there is a character after the @ sign; just
* copy that. This is known not to be '\0' because of the test above.
*/
}
/* At this point *message can't be '\0', even in the bad parameter case
* above where there is a lone '@' at the end of the message string.
*/
msg[i++] = *message++;
}
/* i is always less than (sizeof msg), so: */
msg[i] = '\0';
/* And this is the formatted message. It may be larger than
* PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these
* are not (currently) formatted.
*/
png_warning(png_ptr, msg);
}
#endif /* PNG_WARNINGS_SUPPORTED */
#ifdef PNG_BENIGN_ERRORS_SUPPORTED
void PNGAPI
png_benign_error(png_const_structrp png_ptr, png_const_charp error_message)
{
if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
{
# ifdef PNG_READ_SUPPORTED
if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
png_ptr->chunk_name != 0)
png_chunk_warning(png_ptr, error_message);
else
# endif
png_warning(png_ptr, error_message);
}
else
{
# ifdef PNG_READ_SUPPORTED
if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
png_ptr->chunk_name != 0)
png_chunk_error(png_ptr, error_message);
else
# endif
png_error(png_ptr, error_message);
}
}
void /* PRIVATE */
png_app_warning(png_const_structrp png_ptr, png_const_charp error_message)
{
if (png_ptr->flags & PNG_FLAG_APP_WARNINGS_WARN)
png_warning(png_ptr, error_message);
else
png_error(png_ptr, error_message);
}
void /* PRIVATE */
png_app_error(png_const_structrp png_ptr, png_const_charp error_message)
{
if (png_ptr->flags & PNG_FLAG_APP_ERRORS_WARN)
png_warning(png_ptr, error_message);
else
png_error(png_ptr, error_message);
}
#endif /* BENIGN_ERRORS */
/* These utilities are used internally to build an error message that relates
* to the current chunk. The chunk name comes from png_ptr->chunk_name,
* this is used to prefix the message. The message is limited in length
* to 63 bytes, the name characters are output as hex digits wrapped in []
* if the character is invalid.
*/
#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
static PNG_CONST char png_digit[16] = {
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'A', 'B', 'C', 'D', 'E', 'F'
};
#define PNG_MAX_ERROR_TEXT 196 /* Currently limited be profile_error in png.c */
#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED)
static void /* PRIVATE */
png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp
error_message)
{
png_uint_32 chunk_name = png_ptr->chunk_name;
int iout = 0, ishift = 24;
while (ishift >= 0)
{
int c = (int)(chunk_name >> ishift) & 0xff;
ishift -= 8;
if (isnonalpha(c))
{
buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET;
buffer[iout++] = png_digit[(c & 0xf0) >> 4];
buffer[iout++] = png_digit[c & 0x0f];
buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET;
}
else
{
buffer[iout++] = (char)c;
}
}
if (error_message == NULL)
buffer[iout] = '\0';
else
{
int iin = 0;
buffer[iout++] = ':';
buffer[iout++] = ' ';
while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0')
buffer[iout++] = error_message[iin++];
/* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */
buffer[iout] = '\0';
}
}
#endif /* PNG_WARNINGS_SUPPORTED || PNG_ERROR_TEXT_SUPPORTED */
#if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
PNG_FUNCTION(void,PNGAPI
png_chunk_error,(png_const_structrp png_ptr, png_const_charp error_message),
PNG_NORETURN)
{
char msg[18+PNG_MAX_ERROR_TEXT];
if (png_ptr == NULL)
png_error(png_ptr, error_message);
else
{
png_format_buffer(png_ptr, msg, error_message);
png_error(png_ptr, msg);
}
}
#endif /* PNG_READ_SUPPORTED && PNG_ERROR_TEXT_SUPPORTED */
#ifdef PNG_WARNINGS_SUPPORTED
void PNGAPI
png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message)
{
char msg[18+PNG_MAX_ERROR_TEXT];
if (png_ptr == NULL)
png_warning(png_ptr, warning_message);
else
{
png_format_buffer(png_ptr, msg, warning_message);
png_warning(png_ptr, msg);
}
}
#endif /* PNG_WARNINGS_SUPPORTED */
#ifdef PNG_READ_SUPPORTED
#ifdef PNG_BENIGN_ERRORS_SUPPORTED
void PNGAPI
png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp
error_message)
{
if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
png_chunk_warning(png_ptr, error_message);
else
png_chunk_error(png_ptr, error_message);
}
#endif
#endif /* PNG_READ_SUPPORTED */
void /* PRIVATE */
png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error)
{
/* This is always supported, but for just read or just write it
* unconditionally does the right thing.
*/
# if (defined PNG_READ_SUPPORTED) && (defined PNG_WRITE_SUPPORTED)
if (png_ptr->mode & PNG_IS_READ_STRUCT)
# endif
# ifdef PNG_READ_SUPPORTED
{
if (error < PNG_CHUNK_ERROR)
png_chunk_warning(png_ptr, message);
else
png_chunk_benign_error(png_ptr, message);
}
# endif
# if (defined PNG_READ_SUPPORTED) && (defined PNG_WRITE_SUPPORTED)
else if (!(png_ptr->mode & PNG_IS_READ_STRUCT))
# endif
# ifdef PNG_WRITE_SUPPORTED
{
if (error < PNG_CHUNK_WRITE_ERROR)
png_app_warning(png_ptr, message);
else
png_app_error(png_ptr, message);
}
# endif
}
#ifdef PNG_ERROR_TEXT_SUPPORTED
#ifdef PNG_FLOATING_POINT_SUPPORTED
PNG_FUNCTION(void,
png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN)
{
# define fixed_message "fixed point overflow in "
# define fixed_message_ln ((sizeof fixed_message)-1)
int iin;
char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT];
memcpy(msg, fixed_message, fixed_message_ln);
iin = 0;
if (name != NULL) while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0)
{
msg[fixed_message_ln + iin] = name[iin];
++iin;
}
msg[fixed_message_ln + iin] = 0;
png_error(png_ptr, msg);
}
#endif
#endif
#ifdef PNG_SETJMP_SUPPORTED
/* This API only exists if ANSI-C style error handling is used,
* otherwise it is necessary for png_default_error to be overridden.
*/
jmp_buf* PNGAPI
png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn,
size_t jmp_buf_size)
{
/* From libpng 1.6.0 the app gets one chance to set a 'jmpbuf_size' value
* and it must not change after that. Libpng doesn't care how big the
* buffer is, just that it doesn't change.
*
* If the buffer size is no *larger* than the size of jmp_buf when libpng is
* compiled a built in jmp_buf is returned; this preserves the pre-1.6.0
* semantics that this call will not fail. If the size is larger, however,
* the buffer is allocated and this may fail, causing the function to return
* NULL.
*/
if (png_ptr == NULL)
return NULL;
if (png_ptr->jmp_buf_ptr == NULL)
{
png_ptr->jmp_buf_size = 0; /* not allocated */
if (jmp_buf_size <= (sizeof png_ptr->jmp_buf_local))
png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local;
else
{
png_ptr->jmp_buf_ptr = png_voidcast(jmp_buf *,
png_malloc_warn(png_ptr, jmp_buf_size));
if (png_ptr->jmp_buf_ptr == NULL)
return NULL; /* new NULL return on OOM */
png_ptr->jmp_buf_size = jmp_buf_size;
}
}
else /* Already allocated: check the size */
{
size_t size = png_ptr->jmp_buf_size;
if (size == 0)
{
size = (sizeof png_ptr->jmp_buf_local);
if (png_ptr->jmp_buf_ptr != &png_ptr->jmp_buf_local)
{
/* This is an internal error in libpng: somehow we have been left
* with a stack allocated jmp_buf when the application regained
* control. It's always possible to fix this up, but for the moment
* this is a png_error because that makes it easy to detect.
*/
png_error(png_ptr, "Libpng jmp_buf still allocated");
/* png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; */
}
}
if (size != jmp_buf_size)
{
png_warning(png_ptr, "Application jmp_buf size changed");
return NULL; /* caller will probably crash: no choice here */
}
}
/* Finally fill in the function, now we have a satisfactory buffer. It is
* valid to change the function on every call.
*/
png_ptr->longjmp_fn = longjmp_fn;
return png_ptr->jmp_buf_ptr;
}
void /* PRIVATE */
png_free_jmpbuf(png_structrp png_ptr)
{
if (png_ptr != NULL)
{
jmp_buf *jb = png_ptr->jmp_buf_ptr;
/* A size of 0 is used to indicate a local, stack, allocation of the
* pointer; used here and in png.c
*/
if (jb != NULL && png_ptr->jmp_buf_size > 0)
{
/* This stuff is so that a failure to free the error control structure
* does not leave libpng in a state with no valid error handling: the
* free always succeeds, if there is an error it gets ignored.
*/
if (jb != &png_ptr->jmp_buf_local)
{
/* Make an internal, libpng, jmp_buf to return here */
jmp_buf free_jmp_buf;
if (!setjmp(free_jmp_buf))
{
png_ptr->jmp_buf_ptr = &free_jmp_buf; /* come back here */
png_ptr->jmp_buf_size = 0; /* stack allocation */
png_ptr->longjmp_fn = longjmp;
png_free(png_ptr, jb); /* Return to setjmp on error */
}
}
}
/* *Always* cancel everything out: */
png_ptr->jmp_buf_size = 0;
png_ptr->jmp_buf_ptr = NULL;
png_ptr->longjmp_fn = 0;
}
}
#endif
/* This is the default error handling function. Note that replacements for
* this function MUST NOT RETURN, or the program will likely crash. This
* function is used by default, or if the program supplies NULL for the
* error function pointer in png_set_error_fn().
*/
static PNG_FUNCTION(void /* PRIVATE */,
png_default_error,(png_const_structrp png_ptr, png_const_charp error_message),
PNG_NORETURN)
{
#ifdef PNG_CONSOLE_IO_SUPPORTED
#ifdef PNG_ERROR_NUMBERS_SUPPORTED
/* Check on NULL only added in 1.5.4 */
if (error_message != NULL && *error_message == PNG_LITERAL_SHARP)
{
/* Strip "#nnnn " from beginning of error message. */
int offset;
char error_number[16];
for (offset = 0; offset<15; offset++)
{
error_number[offset] = error_message[offset + 1];
if (error_message[offset] == ' ')
break;
}
if ((offset > 1) && (offset < 15))
{
error_number[offset - 1] = '\0';
fprintf(stderr, "libpng error no. %s: %s",
error_number, error_message + offset + 1);
fprintf(stderr, PNG_STRING_NEWLINE);
}
else
{
fprintf(stderr, "libpng error: %s, offset=%d",
error_message, offset);
fprintf(stderr, PNG_STRING_NEWLINE);
}
}
else
#endif
{
fprintf(stderr, "libpng error: %s", error_message ? error_message :
"undefined");
fprintf(stderr, PNG_STRING_NEWLINE);
}
#else
PNG_UNUSED(error_message) /* Make compiler happy */
#endif
png_longjmp(png_ptr, 1);
}
PNG_FUNCTION(void,PNGAPI
png_longjmp,(png_const_structrp png_ptr, int val),PNG_NORETURN)
{
#ifdef PNG_SETJMP_SUPPORTED
if (png_ptr && png_ptr->longjmp_fn && png_ptr->jmp_buf_ptr)
png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val);
#endif
/* Here if not setjmp support or if png_ptr is null. */
PNG_ABORT();
}
#ifdef PNG_WARNINGS_SUPPORTED
/* This function is called when there is a warning, but the library thinks
* it can continue anyway. Replacement functions don't have to do anything
* here if you don't want them to. In the default configuration, png_ptr is
* not used, but it is passed in case it may be useful.
*/
static void /* PRIVATE */
png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message)
{
#ifdef PNG_CONSOLE_IO_SUPPORTED
# ifdef PNG_ERROR_NUMBERS_SUPPORTED
if (*warning_message == PNG_LITERAL_SHARP)
{
int offset;
char warning_number[16];
for (offset = 0; offset < 15; offset++)
{
warning_number[offset] = warning_message[offset + 1];
if (warning_message[offset] == ' ')
break;
}
if ((offset > 1) && (offset < 15))
{
warning_number[offset + 1] = '\0';
fprintf(stderr, "libpng warning no. %s: %s",
warning_number, warning_message + offset);
fprintf(stderr, PNG_STRING_NEWLINE);
}
else
{
fprintf(stderr, "libpng warning: %s",
warning_message);
fprintf(stderr, PNG_STRING_NEWLINE);
}
}
else
# endif
{
fprintf(stderr, "libpng warning: %s", warning_message);
fprintf(stderr, PNG_STRING_NEWLINE);
}
#else
PNG_UNUSED(warning_message) /* Make compiler happy */
#endif
PNG_UNUSED(png_ptr) /* Make compiler happy */
}
#endif /* PNG_WARNINGS_SUPPORTED */
/* This function is called when the application wants to use another method
* of handling errors and warnings. Note that the error function MUST NOT
* return to the calling routine or serious problems will occur. The return
* method used in the default routine calls longjmp(png_ptr->jmp_buf_ptr, 1)
*/
void PNGAPI
png_set_error_fn(png_structrp png_ptr, png_voidp error_ptr,
png_error_ptr error_fn, png_error_ptr warning_fn)
{
if (png_ptr == NULL)
return;
png_ptr->error_ptr = error_ptr;
png_ptr->error_fn = error_fn;
#ifdef PNG_WARNINGS_SUPPORTED
png_ptr->warning_fn = warning_fn;
#else
PNG_UNUSED(warning_fn)
#endif
}
/* This function returns a pointer to the error_ptr associated with the user
* functions. The application should free any memory associated with this
* pointer before png_write_destroy and png_read_destroy are called.
*/
png_voidp PNGAPI
png_get_error_ptr(png_const_structrp png_ptr)
{
if (png_ptr == NULL)
return NULL;
return ((png_voidp)png_ptr->error_ptr);
}
#ifdef PNG_ERROR_NUMBERS_SUPPORTED
void PNGAPI
png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode)
{
if (png_ptr != NULL)
{
png_ptr->flags &=
((~(PNG_FLAG_STRIP_ERROR_NUMBERS |
PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
}
}
#endif
#if defined PNG_SIMPLIFIED_READ_SUPPORTED ||\
defined PNG_SIMPLIFIED_WRITE_SUPPORTED
/* Currently the above both depend on SETJMP_SUPPORTED, however it would be
* possible to implement without setjmp support just so long as there is some
* way to handle the error return here:
*/
PNG_FUNCTION(void /* PRIVATE */,
png_safe_error,(png_structp png_nonconst_ptr, png_const_charp error_message),
PNG_NORETURN)
{
const png_const_structrp png_ptr = png_nonconst_ptr;
png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
/* An error is always logged here, overwriting anything (typically a warning)
* that is already there:
*/
if (image != NULL)
{
png_safecat(image->message, (sizeof image->message), 0, error_message);
image->warning_or_error |= PNG_IMAGE_ERROR;
/* Retrieve the jmp_buf from within the png_control, making this work for
* C++ compilation too is pretty tricky: C++ wants a pointer to the first
* element of a jmp_buf, but C doesn't tell us the type of that.
*/
if (image->opaque != NULL && image->opaque->error_buf != NULL)
longjmp(png_control_jmp_buf(image->opaque), 1);
/* Missing longjmp buffer, the following is to help debugging: */
{
size_t pos = png_safecat(image->message, (sizeof image->message), 0,
"bad longjmp: ");
png_safecat(image->message, (sizeof image->message), pos,
error_message);
}
}
/* Here on an internal programming error. */
abort();
}
#ifdef PNG_WARNINGS_SUPPORTED
void /* PRIVATE */
png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message)
{
const png_const_structrp png_ptr = png_nonconst_ptr;
png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
/* A warning is only logged if there is no prior warning or error. */
if (image->warning_or_error == 0)
{
png_safecat(image->message, (sizeof image->message), 0, warning_message);
image->warning_or_error |= PNG_IMAGE_WARNING;
}
}
#endif
int /* PRIVATE */
png_safe_execute(png_imagep image_in, int (*function)(png_voidp), png_voidp arg)
{
volatile png_imagep image = image_in;
volatile int result;
volatile png_voidp saved_error_buf;
jmp_buf safe_jmpbuf;
/* Safely execute function(arg) with png_error returning to this function. */
saved_error_buf = image->opaque->error_buf;
result = setjmp(safe_jmpbuf) == 0;
if (result)
{
image->opaque->error_buf = safe_jmpbuf;
result = function(arg);
}
image->opaque->error_buf = saved_error_buf;
/* And do the cleanup prior to any failure return. */
if (!result)
png_image_free(image);
return result;
}
#endif /* SIMPLIFIED READ/WRITE */
#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
Reference in New Issue View Git Blame Copy Permalink