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[devel] Remove png_snprintf, add formatted warning messages.

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This change adds internal APIs to allow png_warning messages to have parameters
 without requiring the host OS to implelment snprintf.  As a side effect the
 dependency of the RFC1132 code on stdio is removed and PNG_NO_WARNINGS does
 actually work now.
This commit is contained in:
John Bowler
2011-05-05 06:49:55 -05:00
committed by Glenn Randers-Pehrson
parent b3b7168077
commit 88b77cc6f3
12 changed files with 562 additions and 256 deletions
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230
pngerror.c
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@@ -89,15 +89,119 @@ png_error,(png_structp png_ptr, png_const_charp error_message),PNG_NORETURN)
PNG_FUNCTION(void,PNGAPI
png_err,(png_structp png_ptr),PNG_NORETURN)
{
/* Prior to 1.5.2 the error_fn received a NULL pointer, expressed erroneouly
* as '\0'. This was apparently an error, and png_default_error will crash
* in this case.
*/
if (png_ptr != NULL && png_ptr->error_fn != NULL)
(*(png_ptr->error_fn))(png_ptr, '\0');
(*(png_ptr->error_fn))(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, '\0');
png_default_error(png_ptr, "");
}
#endif /* PNG_ERROR_TEXT_SUPPORTED */
#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_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;
}
/* 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,
@@ -128,6 +232,115 @@ png_warning(png_structp png_ptr, png_const_charp warning_message)
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_structp png_ptr, png_warning_parameters p,
png_const_charp message)
{
/* The internal buffer is just 128 bytes - enough for all our messages,
* overflow doesn't happen because this code checks!
*/
size_t i;
char msg[128];
for (i=0; i<(sizeof msg)-1 && *message != '\0'; ++i)
{
if (*message == '@')
{
int parameter = -1;
switch (*++message)
{
case '1':
parameter = 0;
break;
case '2':
parameter = 1;
break;
case '\0':
continue; /* To break out of the for loop above. */
default:
break;
}
if (parameter >= 0 && 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':
*/
for (; i<(sizeof msg)-1 && parm != '\0' && parm < pend; ++i)
msg[i] = *parm++;
++message;
continue;
}
/* else not a parameter and there is a character after the @ sign; just
* copy that.
*/
}
/* 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: */
png_warning(png_ptr, msg);
}
#endif /* PNG_WARNINGS_SUPPORTED */
#ifdef PNG_BENIGN_ERRORS_SUPPORTED
@@ -287,7 +500,8 @@ png_default_error,(png_structp png_ptr, png_const_charp error_message),
{
#ifdef PNG_CONSOLE_IO_SUPPORTED
#ifdef PNG_ERROR_NUMBERS_SUPPORTED
if (*error_message == PNG_LITERAL_SHARP)
/* Check on NULL only added in 1.5.3 */
if (error_message != NULL && *error_message == PNG_LITERAL_SHARP)
{
/* Strip "#nnnn " from beginning of error message. */
int offset;
@@ -317,11 +531,11 @@ png_default_error,(png_structp png_ptr, png_const_charp error_message),
else
#endif
{
fprintf(stderr, "libpng error: %s", error_message);
fprintf(stderr, "libpng error: %s", error_message ? error_message :
"undefined");
fprintf(stderr, PNG_STRING_NEWLINE);
}
#endif
#ifndef PNG_CONSOLE_IO_SUPPORTED
#else
PNG_UNUSED(error_message) /* Make compiler happy */
#endif
png_longjmp(png_ptr, 1);
@@ -414,7 +628,11 @@ png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
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
}