Files
zinnia/kernel/core/print.c
T
2026-02-04 01:58:49 +01:00

373 lines
9.6 KiB
C

#include <kernel/console.h>
#include <kernel/panic.h>
#include <kernel/print.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>
static void reverse(char* s) {
int i, j;
char c;
for (i = 0, j = strlen(s) - 1; i < j; i++, j--) {
c = s[i];
s[i] = s[j];
s[j] = c;
}
}
static int pow(int x, unsigned int y) {
if (y == 0)
return 1;
else if ((y % 2) == 0)
return pow(x, y / 2) * pow(x, y / 2);
else
return x * pow(x, y / 2) * pow(x, y / 2);
}
long atol(const char* str, int base) {
size_t len = strlen(str);
int64_t result = 0;
size_t i = 0;
if (str[0] == '-')
i++;
for (; i < len; i++)
result += (str[i] - '0') * pow(base, len - i - 1);
if (str[0] == '-')
result *= -1;
return result;
};
unsigned long atolu(const char* str, int base) {
size_t len = strlen(str);
uint64_t result = 0;
size_t i = 0;
for (; i < len; i++)
result += (str[i] - '0') * pow(base, len - i - 1);
return result;
};
char* ltoa(int64_t value, char* str, int base) {
size_t i;
int64_t sign;
sign = value;
if (base == 10 && sign < 0)
value = -value;
i = 0;
do {
char c = value % base;
if (c > 9)
c += 7;
str[i++] = c + '0';
} while ((value /= base) > 0);
if (base == 10 && sign < 0)
str[i++] = '-';
str[i] = '\0';
reverse(str);
return str;
};
char* lutoa(uint64_t value, char* str, int base) {
size_t i = 0;
do {
char c = value % base;
if (c > 9)
c += 7;
str[i++] = c + '0';
} while ((value /= base) > 0);
str[i] = '\0';
reverse(str);
return str;
};
typedef void (*log_fn_t)(void* ctx, const char* buf, size_t len);
static void kvprintf(log_fn_t callback, void* ctx, const char* restrict fmt, va_list args) {
// Amount of bytes written.
int32_t written = 0;
while (*fmt != '\0') {
size_t maxrem = INT32_MAX - written;
if (fmt[0] != '%' || fmt[1] == '%') {
if (fmt[0] == '%')
fmt++;
size_t amount = 1;
while (fmt[amount] && fmt[amount] != '%')
amount++;
if (maxrem < amount) {
return;
}
callback(ctx, fmt, amount);
fmt += amount;
written += amount;
continue;
}
const char* format_begun_at = fmt++;
bool force_sign = false;
bool blank_sign = false;
bool write_prefix = false;
bool pad_zero = false;
bool has_width = false;
size_t width = 0;
bool has_precision = false;
size_t precision = 0;
size_t size = sizeof(uint32_t);
char number[32];
check_fmt:
memset(number, 0, sizeof(number));
switch (*fmt) {
// Flags
case '+': {
force_sign = true;
fmt++;
goto check_fmt;
}
case ' ': {
blank_sign = true;
fmt++;
goto check_fmt;
}
case '#': {
write_prefix = true;
fmt++;
goto check_fmt;
}
case '0': {
pad_zero = true;
fmt++;
goto check_fmt;
}
// Width
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9': {
has_width = true;
char number[10 + 1] = {0};
size_t idx = 0;
while (*fmt >= '0' && *fmt <= '9') {
number[idx++] = *fmt;
fmt++;
}
width = atolu(number, 10);
goto check_fmt;
}
// Precision
case '.': {
has_precision = true;
fmt++;
if (*fmt == '*') {
precision = (char)va_arg(args, int32_t);
} else {
char number[10 + 1] = {0};
size_t idx = 0;
while (*fmt >= '0' && *fmt <= '9') {
number[idx++] = *fmt;
fmt++;
}
precision = atolu(number, 10);
}
goto check_fmt;
}
// Length
case 'h': {
if (fmt[1] == 'h') {
size = sizeof(uint8_t);
fmt++;
} else
size = sizeof(uint16_t);
fmt++;
goto check_fmt;
}
case 'l': {
// There is no difference between `long int` and `long long int`.
if (fmt[1] == 'l')
fmt++;
fmt++;
size = sizeof(uint64_t);
goto check_fmt;
}
case 'z': {
size = sizeof(size_t);
fmt++;
goto check_fmt;
}
// Character
case 'c': {
char c = (char)va_arg(args, int32_t);
callback(ctx, &c, sizeof(c));
written++;
fmt++;
break;
}
// String of characters
case 's': {
const char* str = va_arg(args, const char*);
if (!str)
str = "(null)";
size_t len = 0;
if (has_width)
len = strnlen(str, width);
else
len = strlen(str);
callback(ctx, str, len);
written += len;
fmt++;
break;
}
// Signed decimal integer
case 'i':
case 'd': {
switch (size) {
case sizeof(int8_t):
ltoa((int8_t)va_arg(args, int32_t), number, 10);
break;
case sizeof(int16_t):
ltoa((int16_t)va_arg(args, int32_t), number, 10);
break;
case sizeof(int32_t):
ltoa((int32_t)va_arg(args, int32_t), number, 10);
break;
default:
ltoa(va_arg(args, int64_t), number, 10);
break;
}
goto print_num;
}
// Unsigned decimal integer
case 'u': {
switch (size) {
case sizeof(uint8_t):
lutoa((uint8_t)va_arg(args, uint32_t), number, 10);
break;
case sizeof(uint16_t):
lutoa((uint16_t)va_arg(args, uint32_t), number, 10);
break;
case sizeof(uint32_t):
lutoa(va_arg(args, uint32_t), number, 10);
break;
case sizeof(uint64_t):
lutoa(va_arg(args, uint64_t), number, 10);
break;
}
goto print_num;
}
// Unsigned hexadecimal integer
case 'X':
case 'x': {
switch (size) {
case sizeof(uint8_t):
lutoa((uint8_t)va_arg(args, uint32_t), number, 16);
break;
case sizeof(uint16_t):
lutoa((uint16_t)va_arg(args, uint32_t), number, 16);
break;
case sizeof(uint32_t):
lutoa(va_arg(args, uint32_t), number, 16);
break;
case sizeof(uint64_t):
lutoa(va_arg(args, uint64_t), number, 16);
break;
}
print_num:
size_t len = strlen(number);
if (has_precision) {
for (size_t i = 0; i < precision - len; i++)
callback(ctx, " ", 1);
}
if (has_width) {
char c = pad_zero ? '0' : ' ';
// We don't have to pad anything.
if (len < width) {
for (size_t i = 0; i < width - len; i++)
callback(ctx, &c, 1);
}
}
if (write_prefix) {
callback(ctx, "0x", 2);
}
if (force_sign) {
char c = '+';
if (number[0] != '-')
callback(ctx, &c, 1);
}
if (blank_sign) {
char c = ' ';
if (number[0] != '-')
callback(ctx, &c, 1);
}
callback(ctx, number, len);
written += len;
fmt++;
break;
}
// Pointer address
case 'p': {
const size_t num = va_arg(args, size_t);
const size_t buf_size = sizeof(size_t) * 2 + 1;
char str[buf_size];
lutoa(num, number, 0x10);
const size_t len = strlen(number); // Get the length of the final number.
for (size_t i = 0; i < buf_size; i++)
str[i] = '0';
size_t offset = sizeof(str) - len - 1;
callback(ctx, str, offset);
callback(ctx, number, len);
fmt++;
written += len;
break;
}
// The number of characters written so far is stored in the pointed location.
case 'n': {
int32_t* const ptr = va_arg(args, int32_t*);
*ptr = written;
fmt++;
break;
}
// No format, just normal text.
default: {
fmt = format_begun_at;
size_t len = strlen(fmt);
callback(ctx, fmt, len);
written += len;
fmt += len;
break;
}
}
}
}
static void printf_console(void*, const char* msg, size_t len) {
console_write(msg, len);
}
void kprintf(const char* message, ...) {
va_list args;
va_start(args, message);
kvprintf(printf_console, nullptr, message, args);
va_end(args);
}