printf.c

#include <stdint.h>
#include <string.h>
#include <stdarg.h>

#include "std.h"
#include "misc.h"
#include "systick.h"
#include "mpconfig.h"
#include "qstr.h"
#include "obj.h"
#include "lcd.h"
#include "usart.h"
#include "usb.h"

#define PF_FLAG_LEFT_ADJUST (0x01)
#define PF_FLAG_SHOW_SIGN   (0x02)
#define PF_FLAG_SPACE_SIGN  (0x04)
#define PF_FLAG_NO_TRAILZ   (0x08)
#define PF_FLAG_ZERO_PAD    (0x10)

// tricky; we compute pad string by: pad_chars + (flags & PF_FLAG_ZERO_PAD)
#define PF_PAD_SIZE PF_FLAG_ZERO_PAD
static const char *pad_chars = "                0000000000000000";

typedef struct _pfenv_t {
    void *data;
    void (*print_strn)(void *, const char *str, unsigned int len);
} pfenv_t;

static void print_str_dummy(void *data, const char *str, unsigned int len) {
}

const pfenv_t pfenv_dummy = {0, print_str_dummy};

static int pfenv_print_strn(const pfenv_t *pfenv, const char *str, unsigned int len, int flags, int width) {
    int pad = width - len;
    if (pad > 0 && (flags & PF_FLAG_LEFT_ADJUST) == 0) {
        while (pad > 0) {
            int p = pad;
            if (p > PF_PAD_SIZE)
                p = PF_PAD_SIZE;
            pfenv->print_strn(pfenv->data, pad_chars + (flags & PF_FLAG_ZERO_PAD), p);
            pad -= p;
        }
    }
    pfenv->print_strn(pfenv->data, str, len);
    while (pad > 0) {
        int p = pad;
        if (p > PF_PAD_SIZE)
            p = PF_PAD_SIZE;
        pfenv->print_strn(pfenv->data, pad_chars, p);
        pad -= p;
    }
    return len;
}

// enough room for 32 signed number
#define INT_BUF_SIZE (12)

static int pfenv_print_int(const pfenv_t *pfenv, unsigned int x, int sgn, int base, int base_char, int flags, int width) {
    char sign = 0;
    if (sgn) {
        if ((int)x < 0) {
            sign = '-';
            x = -x;
        } else if (flags & PF_FLAG_SHOW_SIGN) {
            sign = '+';
        } else if (flags & PF_FLAG_SPACE_SIGN) {
            sign = ' ';
        }