libc: improved printf

This commit is contained in:
K. Lange 2021-04-06 21:18:44 +09:00
parent cf045ced81
commit 79da53276e
1 changed files with 91 additions and 64 deletions

View File

@ -2,36 +2,22 @@
#include <string.h> #include <string.h>
#include <va_list.h> #include <va_list.h>
static void print_dec(unsigned int value, unsigned int width, char * buf, int * ptr, int fill_zero, int align_right, int precision) { static void print_dec(unsigned long long value, unsigned int width, char * buf, int * ptr, int fill_zero, int align_right, int precision) {
unsigned int n_width = 1; unsigned long long n_width = 1;
unsigned int i = 9; unsigned long long i = 9;
if (precision == -1) precision = 1; if (precision == -1) precision = 1;
if (value == 0) { if (value == 0) {
n_width = 0; n_width = 0;
} else if (value < 10UL) {
n_width = 1;
} else if (value < 100UL) {
n_width = 2;
} else if (value < 1000UL) {
n_width = 3;
} else if (value < 10000UL) {
n_width = 4;
} else if (value < 100000UL) {
n_width = 5;
} else if (value < 1000000UL) {
n_width = 6;
} else if (value < 10000000UL) {
n_width = 7;
} else if (value < 100000000UL) {
n_width = 8;
} else if (value < 1000000000UL) {
n_width = 9;
} else { } else {
n_width = 10; unsigned long long val = value;
while (val >= 10UL) {
val /= 10UL;
n_width++;
}
} }
if (n_width < (unsigned int)precision) n_width = precision; if (n_width < (unsigned long long)precision) n_width = precision;
int printed = 0; int printed = 0;
if (align_right) { if (align_right) {
@ -43,8 +29,8 @@ static void print_dec(unsigned int value, unsigned int width, char * buf, int *
i = n_width; i = n_width;
while (i > 0) { while (i > 0) {
unsigned int n = value / 10; unsigned long long n = value / 10;
int r = value % 10; long long r = value % 10;
buf[*ptr + i - 1] = r + '0'; buf[*ptr + i - 1] = r + '0';
i--; i--;
value = n; value = n;
@ -53,15 +39,15 @@ static void print_dec(unsigned int value, unsigned int width, char * buf, int *
} else { } else {
i = n_width; i = n_width;
while (i > 0) { while (i > 0) {
unsigned int n = value / 10; unsigned long long n = value / 10;
int r = value % 10; long long r = value % 10;
buf[*ptr + i - 1] = r + '0'; buf[*ptr + i - 1] = r + '0';
i--; i--;
value = n; value = n;
printed++; printed++;
} }
*ptr += n_width; *ptr += n_width;
while (printed < (int)width) { while (printed < (long long)width) {
buf[*ptr] = fill_zero ? '0' : ' '; buf[*ptr] = fill_zero ? '0' : ' ';
*ptr += 1; *ptr += 1;
printed += 1; printed += 1;
@ -72,26 +58,26 @@ static void print_dec(unsigned int value, unsigned int width, char * buf, int *
/* /*
* Hexadecimal to string * Hexadecimal to string
*/ */
static void print_hex(unsigned int value, unsigned int width, char * buf, int * ptr) { static void print_hex(unsigned long long value, unsigned int width, char * buf, int * ptr) {
int i = width; int i = width;
if (i == 0) i = 8; if (i == 0) i = 8;
unsigned int n_width = 1; unsigned long long n_width = 1;
unsigned int j = 0x0F; unsigned long long j = 0x0F;
while (value > j && j < UINT32_MAX) { while (value > j && j < UINT64_MAX) {
n_width += 1; n_width += 1;
j *= 0x10; j *= 0x10;
j += 0x0F; j += 0x0F;
} }
while (i > (int)n_width) { while (i > (long long)n_width) {
buf[*ptr] = '0'; buf[*ptr] = '0';
*ptr += 1; *ptr += 1;
i--; i--;
} }
i = (int)n_width; i = (long long)n_width;
while (i-- > 0) { while (i-- > 0) {
buf[*ptr] = "0123456789abcdef"[(value>>(i*4))&0xF]; buf[*ptr] = "0123456789abcdef"[(value>>(i*4))&0xF];
*ptr += + 1; *ptr += + 1;
@ -175,16 +161,7 @@ int xvasprintf(char * buf, const char * fmt, va_list args) {
{ {
size_t count = 0; size_t count = 0;
if (big) { if (big) {
wchar_t * ws = (wchar_t *)va_arg(args, wchar_t *); return -1;
if (ws == NULL) {
ws = L"(null)";
}
size_t count = 0;
while (*ws) {
*b++ = *ws++;
count++;
if (arg_width && count == arg_width) break;
}
} else { } else {
s = (char *)va_arg(args, char *); s = (char *)va_arg(args, char *);
if (s == NULL) { if (s == NULL) {
@ -218,23 +195,26 @@ int xvasprintf(char * buf, const char * fmt, va_list args) {
if (!arg_width) { if (!arg_width) {
arg_width = 8; arg_width = 8;
alt = 1; alt = 1;
if (sizeof(void*) == sizeof(long long)) big = 2;
} }
case 'x': /* Hexadecimal number */ case 'x': /* Hexadecimal number */
if (alt) { {
*b++ = '0'; if (alt) {
*b++ = 'x'; *b++ = '0';
} *b++ = 'x';
i = b - buf;
if (big == 2) {
unsigned long long val = (unsigned long long)va_arg(args, unsigned long long);
if (val > 0xFFFFFFFF) {
print_hex(val >> 32, arg_width > 8 ? (arg_width - 8) : 0, buf, &i);
} }
print_hex(val & 0xFFFFFFFF, arg_width > 8 ? 8 : arg_width, buf, &i); i = b - buf;
} else { unsigned long long val;
print_hex((unsigned long)va_arg(args, unsigned long), arg_width, buf, &i); if (big == 2) {
val = (unsigned long long)va_arg(args, unsigned long long);
} else if (big == 1) {
val = (unsigned long)va_arg(args, unsigned long);
} else {
val = (unsigned int)va_arg(args, unsigned int);
}
print_hex(val, arg_width, buf, &i);
b = buf + i;
} }
b = buf + i;
break; break;
case 'i': case 'i':
case 'd': /* Decimal number */ case 'd': /* Decimal number */
@ -242,8 +222,10 @@ int xvasprintf(char * buf, const char * fmt, va_list args) {
long long val; long long val;
if (big == 2) { if (big == 2) {
val = (long long)va_arg(args, long long); val = (long long)va_arg(args, long long);
} else { } else if (big == 1) {
val = (long)va_arg(args, long); val = (long)va_arg(args, long);
} else {
val = (int)va_arg(args, int);
} }
if (val < 0) { if (val < 0) {
*b++ = '-'; *b++ = '-';
@ -262,8 +244,10 @@ int xvasprintf(char * buf, const char * fmt, va_list args) {
unsigned long long val; unsigned long long val;
if (big == 2) { if (big == 2) {
val = (unsigned long long)va_arg(args, unsigned long long); val = (unsigned long long)va_arg(args, unsigned long long);
} else { } else if (big == 1) {
val = (unsigned long)va_arg(args, unsigned long); val = (unsigned long)va_arg(args, unsigned long);
} else {
val = (unsigned int)va_arg(args, unsigned int);
} }
print_dec(val, arg_width, buf, &i, fill_zero, align, precision); print_dec(val, arg_width, buf, &i, fill_zero, align, precision);
} }
@ -272,20 +256,63 @@ int xvasprintf(char * buf, const char * fmt, va_list args) {
case 'g': /* supposed to also support e */ case 'g': /* supposed to also support e */
case 'f': case 'f':
{ {
if (precision == -1) precision = 8;
double val = (double)va_arg(args, double); double val = (double)va_arg(args, double);
if (val < 0) { uint64_t asBits;
memcpy(&asBits,&val,sizeof(double));
#define SIGNBIT(d) (d & 0x8000000000000000UL)
/* Extract exponent */
int64_t exponent = (asBits & 0x7ff0000000000000UL) >> 52;
/* Fraction part */
uint64_t fraction = (asBits & 0x000fffffffffffffUL);
if (exponent == 0x7ff) {
if (!fraction) {
if (SIGNBIT(asBits)) {
*b++ = '-';
}
*b++ = 'i';
*b++ = 'n';
*b++ = 'f';
} else {
*b++ = 'n';
*b++ = 'a';
*b++ = 'n';
}
break;
} else if (exponent == 0 && fraction == 0) {
if (SIGNBIT(asBits)) {
*b++ = '-';
}
*b++ = '0';
break;
}
/* Okay, now we can do some real work... */
int isNegative = !!SIGNBIT(asBits);
if (isNegative) {
*b++ = '-'; *b++ = '-';
val = -val; val = -val;
} }
i = b - buf; i = b - buf;
print_dec((long)val, arg_width, buf, &i, fill_zero, align, 1); print_dec((unsigned long long)val, arg_width, buf, &i, fill_zero, align, 1);
b = buf + i; b = buf + i;
*b++ = '.'; *b++ = '.';
i = b - buf; i = b - buf;
for (int j = 0; j < ((precision > -1 && precision < 8) ? precision : 8); ++j) { for (int j = 0; j < ((precision > -1 && precision < 16) ? precision : 16); ++j) {
if ((int)(val * 100000.0) % 100000 == 0 && j != 0) break; if ((unsigned long long)(val * 100000.0) % 100000 == 0 && j != 0) break;
val = val - (unsigned long long)val;
val *= 10.0; val *= 10.0;
print_dec((int)(val) % 10, 0, buf, &i, 0, 0, 1); double roundy = ((double)(val - (unsigned long long)val) - 0.99999);
if (roundy < 0.00001 && roundy > -0.00001) {
print_dec((unsigned long long)(val) % 10 + 1, 0, buf, &i, 0, 0, 1);
break;
}
print_dec((unsigned long long)(val) % 10, 0, buf, &i, 0, 0, 1);
} }
b = buf + i; b = buf + i;
} }