chibicc/unicode.c

#include "chibicc.h"

// Encode a given character in UTF-8.
int encode_utf8(char *buf, uint32_t c) {
  if (c <= 0x7F) {
    buf[0] = c;
    return 1;
  }

  if (c <= 0x7FF) {
    buf[0] = 0b11000000 | (c >> 6);
    buf[1] = 0b10000000 | (c & 0b00111111);
    return 2;
  }

  if (c <= 0xFFFF) {
    buf[0] = 0b11100000 | (c >> 12);
    buf[1] = 0b10000000 | ((c >> 6) & 0b00111111);
    buf[2] = 0b10000000 | (c & 0b00111111);
    return 3;
  }

  buf[0] = 0b11110000 | (c >> 18);
  buf[1] = 0b10000000 | ((c >> 12) & 0b00111111);
  buf[2] = 0b10000000 | ((c >> 6) & 0b00111111);
  buf[3] = 0b10000000 | (c & 0b00111111);
  return 4;
}