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#include "Python.h"
#include <ctype.h>

/* snprintf() wrappers.  If the platform has vsnprintf, we use it, else we
   emulate it in a half-hearted way.  Even if the platform has it, we wrap
   it because platforms differ in what vsnprintf does in case the buffer
   is too small:  C99 behavior is to return the number of characters that
   would have been written had the buffer not been too small, and to set
   the last byte of the buffer to \0.  At least MS _vsnprintf returns a
   negative value instead, and fills the entire buffer with non-\0 data.

   The wrappers ensure that str[size-1] is always \0 upon return.

   PyOS_snprintf and PyOS_vsnprintf never write more than size bytes
   (including the trailing '\0') into str.

   If the platform doesn't have vsnprintf, and the buffer size needed to
   avoid truncation exceeds size by more than 512, Python aborts with a
   Py_FatalError.

   Return value (rv):

	When 0 <= rv < size, the output conversion was unexceptional, and
	rv characters were written to str (excluding a trailing \0 byte at
	str[rv]).

	When rv >= size, output conversion was truncated, and a buffer of
	size rv+1 would have been needed to avoid truncation.  str[size-1]
	is \0 in this case.

	When rv < 0, "something bad happened".  str[size-1] is \0 in this
	case too, but the rest of str is unreliable.  It could be that
	an error in format codes was detected by libc, or on platforms
	with a non-C99 vsnprintf simply that the buffer wasn't big enough
	to avoid truncation, or on platforms without any vsnprintf that
	PyMem_Malloc couldn't obtain space for a temp buffer.

   CAUTION:  Unlike C99, str != NULL and size > 0 are required.
*/

int
PyOS_snprintf(char *str, size_t size, const  char  *format, ...)
{
	int rc;
	va_list va;

	va_start(va, format);
	rc = PyOS_vsnprintf(str, size, format, va);
	va_end(va);
	return rc;
}

int
PyOS_vsnprintf(char *str, size_t size, const char  *format, va_list va)
{
	int len;  /* # bytes written, excluding \0 */
#ifndef HAVE_SNPRINTF
	char *buffer;
#endif
	assert(str != NULL);
	assert(size > 0);
	assert(format != NULL);

#ifdef HAVE_SNPRINTF
	len = vsnprintf(str, size, format, va);
#else
	/* Emulate it. */
	buffer = PyMem_MALLOC(size + 512);
	if (buffer == NULL) {
		len = -666;
		goto Done;
	}

	len = vsprintf(buffer, format, va);
	if (len < 0)
		/* ignore the error */;

	else if ((size_t)len >= size + 512)
		Py_FatalError("Buffer overflow in PyOS_snprintf/PyOS_vsnprintf");

	else {
		const size_t to_copy = (size_t)len < size ?
					(size_t)len : size - 1;
		assert(to_copy < size);
		memcpy(str, buffer, to_copy);
		str[to_copy] = '\0';
	}
	PyMem_FREE(buffer);
Done:
#endif
	str[size-1] = '\0';
	return len;
}
t/src/engine?id=d68c584feb4a01fa5b511701996d3833968ccae1'>mergeWilliam Deegan2017-02-201-1/+1 |\ | * Fix missing quote in user documentation about Substfilephilippe coval2017-01-201-1/+1 | * Fix merge errorsWilliam Deegan2017-01-151-4/+0 | * merge headsWilliam Deegan2017-01-1515-295/+577 | |\ | * | changes to force SCons to respect RANLIB when initializing ar toolsWilliam Deegan2017-01-152-3/+3 * | | PY3 porting work. Also moved comments for methods into docstringsWilliam Deegan2017-02-202-58/+164 * | | Merged scons/scons into defaultWilliam Deegan2017-01-1412-285/+550 |\ \ \ | | |/ | |/| | * | Make c++ proxy files to the cxx formsJason Kenny2016-12-2312-285/+550 * | | Added some details comments to _function_contents() which is used to generate...William Deegan2016-12-232-24/+6 * | | Added some details comments to _function_contents() which is used to generate...William Deegan2016-12-231-3/+4 * | | Added some details comments to _function_contents() which is used to generate...William Deegan2016-12-221-6/+15 * | | Added some details comments to _code_contents() which is used to generate act...William Deegan2016-12-221-14/+38 * | | fixes get function/object signatures working on python 3 (and 2.7)William Deegan2016-12-212-17/+29 |/ / * | Merged in mbyt/scons/python3win32 (pull request #369)William Deegan2016-12-201-9/+21 |\ \ | * | fixing typo, it must be _scons_filepython3win32mbyt2016-11-291-1/+1 | * | the file builtin does not exist in python3mbyt2016-10-191-9/+21 * | | merge headsWilliam Deegan2016-11-283-4/+5 |\ \ \ | |_|/ |/| | | * | Fix tests failing on win32 AR and Fortran and M4William Deegan2016-11-282-3/+3 | * | Add better error messaging when missing (or surplus) shared library targets w...William Deegan2016-11-281-1/+2 | * | update from upstreamWilliam Deegan2016-11-251-2/+2 | |\ \ | * \ \ Merged scons/scons into defaultWilliam Deegan2016-10-17