ladybird/AK/printf.cpp

182 lines
4.8 KiB
C++
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typedef unsigned char byte;
typedef unsigned short word;
typedef unsigned int dword;
ALWAYS_INLINE size_t strlen(const char* str)
{
size_t len = 0;
while (*(str++))
++len;
return len;
}
static constexpr const char* h = "0123456789abcdef";
template<typename PutChFunc>
ALWAYS_INLINE int printHex(PutChFunc putch, char*& bufptr, dword number, byte fields)
{
int ret = 0;
byte shr_count = fields * 4;
while (shr_count) {
shr_count -= 4;
putch(bufptr, h[(number >> shr_count) & 0x0F]);
++ret;
}
return ret;
}
template<typename PutChFunc>
ALWAYS_INLINE int printNumber(PutChFunc putch, char*& bufptr, dword number, bool leftPad, bool zeroPad, dword fieldWidth)
{
dword divisor = 1000000000;
char ch;
char padding = 1;
char buf[16];
char* p = buf;
for (;;) {
ch = '0' + (number / divisor);
number %= divisor;
if (ch != '0')
padding = 0;
if (!padding || divisor == 1)
*(p++) = ch;
if (divisor == 1)
break;
divisor /= 10;
}
size_t numlen = p - buf;
if (!fieldWidth || fieldWidth < numlen)
fieldWidth = numlen;
if (!leftPad) {
for (unsigned i = 0; i < fieldWidth - numlen; ++i) {
putch(bufptr, zeroPad ? '0' : ' ');
}
}
for (unsigned i = 0; i < numlen; ++i) {
putch(bufptr, buf[i]);
}
if (leftPad) {
for (unsigned i = 0; i < fieldWidth - numlen; ++i) {
putch(bufptr, ' ');
}
}
return fieldWidth;
}
template<typename PutChFunc>
ALWAYS_INLINE int printString(PutChFunc putch, char*& bufptr, const char* str, bool leftPad, dword fieldWidth)
{
size_t len = strlen(str);
if (!fieldWidth || fieldWidth < len)
fieldWidth = len;
if (!leftPad) {
for (unsigned i = 0; i < fieldWidth - len; ++i)
putch(bufptr, ' ');
}
for (unsigned i = 0; i < len; ++i) {
putch(bufptr, str[i]);
}
if (leftPad) {
for (unsigned i = 0; i < fieldWidth - len; ++i)
putch(bufptr, ' ');
}
return fieldWidth;
}
template<typename PutChFunc>
ALWAYS_INLINE int printSignedNumber(PutChFunc putch, char*& bufptr, int number, bool leftPad, bool zeroPad, dword fieldWidth)
{
if (number < 0) {
putch(bufptr, '-');
return printNumber(putch, bufptr, 0 - number, leftPad, zeroPad, fieldWidth) + 1;
}
return printNumber(putch, bufptr, number, leftPad, zeroPad, fieldWidth);
}
template<typename PutChFunc>
ALWAYS_INLINE int printfInternal(PutChFunc putch, char* buffer, const char*& fmt, char*& ap)
{
const char *p;
int ret = 0;
char* bufptr = buffer;
for (p = fmt; *p; ++p) {
bool leftPad = false;
bool zeroPad = false;
unsigned fieldWidth = 0;
if (*p == '%' && *(p + 1)) {
one_more:
++p;
if (*p == ' ') {
leftPad = true;
if (*(p + 1))
goto one_more;
}
if (!zeroPad && !fieldWidth && *p == '0') {
zeroPad = true;
if (*(p + 1))
goto one_more;
}
if (*p >= '0' && *p <= '9') {
fieldWidth *= 10;
fieldWidth += *p - '0';
if (*(p + 1))
goto one_more;
}
switch( *p )
{
case 's':
{
const char* sp = va_arg(ap, const char*);
ret += printString(putch, bufptr, sp ? sp : "(null)", leftPad, fieldWidth);
}
break;
case 'd':
ret += printSignedNumber(putch, bufptr, va_arg(ap, int), leftPad, zeroPad, fieldWidth);
break;
case 'u':
ret += printNumber(putch, bufptr, va_arg(ap, dword), leftPad, zeroPad, fieldWidth);
break;
case 'x':
ret += printHex(putch, bufptr, va_arg(ap, dword), 8);
break;
case 'w':
ret += printHex(putch, bufptr, va_arg(ap, int), 4);
break;
case 'b':
ret += printHex(putch, bufptr, va_arg(ap, int), 2);
break;
case 'c':
putch(bufptr, (char)va_arg(ap, int));
++ret;
break;
case 'p':
putch(bufptr, '0');
putch(bufptr, 'x');
ret += 2;
ret += printHex(putch, bufptr, va_arg(ap, dword), 8);
break;
}
}
else {
putch(bufptr, *p);
++ret;
}
}
return ret;
}