(svn r19149) -Codechange: make our vsnprintf implementation for Windows more POSIX compliant (adf88)

This commit is contained in:
rubidium 2010-02-17 15:07:09 +00:00
parent 1b0e78c588
commit a6112670d0
1 changed files with 32 additions and 8 deletions

View File

@ -20,6 +20,10 @@
#include <stdarg.h>
#include <ctype.h> /* required for tolower() */
#ifdef _MSC_VER
#include <errno.h> // required by vsnprintf implementation for MSVC
#endif
/**
* Safer implementation of vsnprintf; same as vsnprintf except:
* - last instead of size, i.e. replace sizeof with lastof.
@ -219,17 +223,37 @@ int CDECL snprintf(char *str, size_t size, const char *format, ...)
#endif /* MinGW Runtime < 3.14 */
#ifdef _MSC_VER
/* *nprintf broken, not POSIX compliant, MSDN description
* - If len < count, then len characters are stored in buffer, a null-terminator is appended, and len is returned.
* - If len = count, then len characters are stored in buffer, no null-terminator is appended, and len is returned.
* - If len > count, then count characters are stored in buffer, no null-terminator is appended, and a negative value is returned
/**
* Almost POSIX compliant implementation of \c vsnprintf for VC compiler.
* The difference is in the value returned on output truncation. This
* implementation returns size whereas a POSIX implementation returns
* size or more (the number of bytes that would be written to str
* had size been sufficiently large excluding the terminating null byte).
*/
int CDECL vsnprintf(char *str, size_t size, const char *format, va_list ap)
{
int ret;
ret = _vsnprintf(str, size, format, ap);
if (ret < 0 || ret == size) str[size - 1] = '\0';
return ret;
if (size == 0) return 0;
errno = 0;
int ret = _vsnprintf(str, size, format, ap);
if (ret < 0) {
if (errno != ERANGE) {
/* There's a formatting error, better get that looked
* at properly instead of ignoring it. */
NOT_REACHED();
}
} else if ((size_t)ret < size) {
/* The buffer is big enough for the number of
* characers stored (excluding null), i.e.
* the string has been null-terminated. */
return ret;
}
/* The buffer is too small for _vsnprintf to write the
* null-terminator at its end and return size. */
str[size - 1] = '\0';
return size;
}
#endif /* _MSC_VER */