in RISC-V_RV32_THEAD_SMART_CDS/libs/libc/printf.c [671:951]
static int _vsnprintf(out_fct_type out, char* buffer, const size_t maxlen, const char* format, va_list va)
{
unsigned int flags, width, precision, n;
size_t idx = 0U;
if (!buffer) {
// use null output function
out = _out_null;
}
while (*format)
{
// format specifier? %[flags][width][.precision][length]
if (*format != '%') {
// no
out(*format, buffer, idx++, maxlen);
format++;
continue;
}
else {
// yes, evaluate it
format++;
}
// evaluate flags
flags = 0U;
do {
switch (*format) {
case '0': flags |= FLAGS_ZEROPAD; format++; n = 1U; break;
case '-': flags |= FLAGS_LEFT; format++; n = 1U; break;
case '+': flags |= FLAGS_PLUS; format++; n = 1U; break;
case ' ': flags |= FLAGS_SPACE; format++; n = 1U; break;
case '#': flags |= FLAGS_HASH; format++; n = 1U; break;
default : n = 0U; break;
}
} while (n);
// evaluate width field
width = 0U;
if (_is_digit(*format)) {
width = _atoi(&format);
}
else if (*format == '*') {
const int w = va_arg(va, int);
if (w < 0) {
flags |= FLAGS_LEFT; // reverse padding
width = (unsigned int)-w;
}
else {
width = (unsigned int)w;
}
format++;
}
// evaluate precision field
precision = 0U;
if (*format == '.') {
flags |= FLAGS_PRECISION;
format++;
if (_is_digit(*format)) {
precision = _atoi(&format);
}
else if (*format == '*') {
const int prec = (int)va_arg(va, int);
precision = prec > 0 ? (unsigned int)prec : 0U;
format++;
}
}
// evaluate length field
switch (*format) {
case 'l' :
flags |= FLAGS_LONG;
format++;
if (*format == 'l') {
flags |= FLAGS_LONG_LONG;
format++;
}
break;
case 'h' :
flags |= FLAGS_SHORT;
format++;
if (*format == 'h') {
flags |= FLAGS_CHAR;
format++;
}
break;
#if defined(PRINTF_SUPPORT_PTRDIFF_T)
case 't' :
flags |= (sizeof(ptrdiff_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG);
format++;
break;
#endif
case 'j' :
flags |= (sizeof(intmax_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG);
format++;
break;
case 'z' :
flags |= (sizeof(size_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG);
format++;
break;
default :
break;
}
// evaluate specifier
switch (*format) {
case 'd' :
case 'i' :
case 'u' :
case 'x' :
case 'X' :
case 'o' :
case 'b' : {
// set the base
unsigned int base;
if (*format == 'x' || *format == 'X') {
base = 16U;
}
else if (*format == 'o') {
base = 8U;
}
else if (*format == 'b') {
base = 2U;
}
else {
base = 10U;
flags &= ~FLAGS_HASH; // no hash for dec format
}
// uppercase
if (*format == 'X') {
flags |= FLAGS_UPPERCASE;
}
// no plus or space flag for u, x, X, o, b
if ((*format != 'i') && (*format != 'd')) {
flags &= ~(FLAGS_PLUS | FLAGS_SPACE);
}
// ignore '0' flag when precision is given
if (flags & FLAGS_PRECISION) {
flags &= ~FLAGS_ZEROPAD;
}
// convert the integer
if ((*format == 'i') || (*format == 'd')) {
// signed
if (flags & FLAGS_LONG_LONG) {
#if defined(PRINTF_SUPPORT_LONG_LONG)
const long long value = va_arg(va, long long);
idx = _ntoa_long_long(out, buffer, idx, maxlen, (unsigned long long)(value > 0 ? value : 0 - value), value < 0, base, precision, width, flags);
#endif
}
else if (flags & FLAGS_LONG) {
const long value = va_arg(va, long);
idx = _ntoa_long(out, buffer, idx, maxlen, (unsigned long)(value > 0 ? value : 0 - value), value < 0, base, precision, width, flags);
}
else {
const int value = (flags & FLAGS_CHAR) ? (char)va_arg(va, int) : (flags & FLAGS_SHORT) ? (short int)va_arg(va, int) : va_arg(va, int);
idx = _ntoa_long(out, buffer, idx, maxlen, (unsigned int)(value > 0 ? value : 0 - value), value < 0, base, precision, width, flags);
}
}
else {
// unsigned
if (flags & FLAGS_LONG_LONG) {
#if defined(PRINTF_SUPPORT_LONG_LONG)
idx = _ntoa_long_long(out, buffer, idx, maxlen, va_arg(va, unsigned long long), false, base, precision, width, flags);
#endif
}
else if (flags & FLAGS_LONG) {
idx = _ntoa_long(out, buffer, idx, maxlen, va_arg(va, unsigned long), false, base, precision, width, flags);
}
else {
const unsigned int value = (flags & FLAGS_CHAR) ? (unsigned char)va_arg(va, unsigned int) : (flags & FLAGS_SHORT) ? (unsigned short int)va_arg(va, unsigned int) : va_arg(va, unsigned int);
idx = _ntoa_long(out, buffer, idx, maxlen, value, false, base, precision, width, flags);
}
}
format++;
break;
}
#if defined(PRINTF_SUPPORT_FLOAT)
case 'f' :
case 'F' :
if (*format == 'F') flags |= FLAGS_UPPERCASE;
idx = _ftoa(out, buffer, idx, maxlen, va_arg(va, double), precision, width, flags);
format++;
break;
#if defined(PRINTF_SUPPORT_EXPONENTIAL)
case 'e':
case 'E':
case 'g':
case 'G':
if ((*format == 'g')||(*format == 'G')) flags |= FLAGS_ADAPT_EXP;
if ((*format == 'E')||(*format == 'G')) flags |= FLAGS_UPPERCASE;
idx = _etoa(out, buffer, idx, maxlen, va_arg(va, double), precision, width, flags);
format++;
break;
#endif // PRINTF_SUPPORT_EXPONENTIAL
#endif // PRINTF_SUPPORT_FLOAT
case 'c' : {
unsigned int l = 1U;
// pre padding
if (!(flags & FLAGS_LEFT)) {
while (l++ < width) {
out(' ', buffer, idx++, maxlen);
}
}
// char output
out((char)va_arg(va, int), buffer, idx++, maxlen);
// post padding
if (flags & FLAGS_LEFT) {
while (l++ < width) {
out(' ', buffer, idx++, maxlen);
}
}
format++;
break;
}
case 's' : {
const char* p = va_arg(va, char*);
unsigned int l = _strnlen_s(p, precision ? precision : (size_t)-1);
// pre padding
if (flags & FLAGS_PRECISION) {
l = (l < precision ? l : precision);
}
if (!(flags & FLAGS_LEFT)) {
while (l++ < width) {
out(' ', buffer, idx++, maxlen);
}
}
// string output
while ((*p != 0) && (!(flags & FLAGS_PRECISION) || precision--)) {
out(*(p++), buffer, idx++, maxlen);
}
// post padding
if (flags & FLAGS_LEFT) {
while (l++ < width) {
out(' ', buffer, idx++, maxlen);
}
}
format++;
break;
}
case 'p' : {
width = sizeof(void*) * 2U;
flags |= FLAGS_ZEROPAD | FLAGS_UPPERCASE;
#if defined(PRINTF_SUPPORT_LONG_LONG)
const bool is_ll = sizeof(uintptr_t) == sizeof(long long);
if (is_ll) {
idx = _ntoa_long_long(out, buffer, idx, maxlen, (uintptr_t)va_arg(va, void*), false, 16U, precision, width, flags);
}
else {
#endif
idx = _ntoa_long(out, buffer, idx, maxlen, (unsigned long)((uintptr_t)va_arg(va, void*)), false, 16U, precision, width, flags);
#if defined(PRINTF_SUPPORT_LONG_LONG)
}
#endif
format++;
break;
}
case '%' :
out('%', buffer, idx++, maxlen);
format++;
break;
default :
out(*format, buffer, idx++, maxlen);
format++;
break;
}
}
// termination
out((char)0, buffer, idx < maxlen ? idx : maxlen - 1U, maxlen);
// return written chars without terminating \0
return (int)idx;
}