#include #include #include size_t mbrtoc16( char16_t *restrict pc16, char const *restrict s, size_t n, mbstate_t *restrict ps ) { // Figure out the conversion state static mbstate_t static_mbstate = {0}; if(ps == NULL) ps = &static_mbstate; if(s == NULL) { *ps = (mbstate_t) {0xd800}; return 0; } // Check leftovers, using 0xd800 as "no leftover" marker because it // doesn't encode a valid character. if(ps->leftover == 0xd800) { // Decode the UTF-8 encoded codepoint char32_t code_point; int mblen = utf8_chdec((char8_t *)s, n, &code_point); if(mblen == UNI_ESTRLN) return (size_t)(-2); if(mblen <= 0) goto invalid_seq; // Encode the codepoint into UTF-16 string char16_t str[2]; int c16len = utf16_chenc(str, 2, code_point); if(c16len <= 0) goto invalid_seq; // Assign the decoded UTF-16 character, decide leftover if(pc16 != NULL) *pc16 = str[0]; ps->leftover = (c16len == 2? str[1] : 0xd800); return (size_t)mblen; } else { // Otherwise use and reset the leftover if(pc16 != NULL) *pc16 = ps->leftover; ps->leftover = 0xd800; return (size_t)(-3); } invalid_seq: errno = EILSEQ; return (size_t)(-1); } size_t c16rtomb( char *restrict s, char16_t c16, mbstate_t *restrict ps ) { // Figure out conversion state static mbstate_t static_mbstate = {0}; if(ps == NULL) ps = &static_mbstate; if(s == NULL) { *ps = (mbstate_t) {0xd800}; return 0; } char32_t codepoint_to_write; // Check whether a high surrogate was detected in a previous call to the // function. If not, the high_surrogate value is 0xd800 if(ps->high_surrogate == 0xd800) { // If c16 is a surrogate record it, or throw an error if(uni_is_hsur(c16)) { ps->high_surrogate = c16; return 0; } else if(uni_is_lsur(c16)) { goto invalid_char; } // We'll just write c16 codepoint_to_write = c16; } // If high surrogate exists, the next character must be a low surrogate // so we'll write a codepoint made out of high and low surrogates else if(uni_is_lsur(c16)) { codepoint_to_write = uni_surtoc(ps->high_surrogate, c16); } else goto invalid_char; // Write the codepoint that we decided to write to multibyte string int written_len = utf8_chenc((char8_t *)s, 4, codepoint_to_write); if(written_len < 0) { goto invalid_char; } s[written_len] = 0; return (size_t)written_len; invalid_char: errno = EILSEQ; return (size_t)(-1); } size_t mbrtoc32( char32_t *restrict pc32, char const *restrict s, size_t n, mbstate_t *restrict ps ) { if(s == NULL) { *ps = (mbstate_t) {0}; return 0; } size_t nbytes; // Decode the first byte of UTF-8 sequence unsigned byte0 = *s; if (0x00 <= byte0 && byte0 < 0x80) nbytes = 1; else if(0xc0 <= byte0 && byte0 < 0xe0) nbytes = 2; else if(0xe0 <= byte0 && byte0 < 0xf0) nbytes = 3; else if(0xf0 <= byte0 && byte0 < 0xf8) nbytes = 4; else goto encoding_error; unsigned nbytesreq = nbytes; if(n < nbytesreq) { return (size_t)(-2); } char32_t cp = byte0; switch(nbytesreq) { case 2: cp &= 0x1f; break; case 3: cp &= 0x0f; break; case 4: cp &= 0x07; break; } while(--nbytesreq) cp |= (cp << 6) | ((*++s) & 0x3f); if(0xdc00 <= cp && cp <= 0xe000) goto encoding_error; // Overloing seqs if(cp < 0x80 && nbytes > 1) goto encoding_error; if(cp < 0x800 && nbytes > 2) goto encoding_error; if(cp < 0x10000 && nbytes > 3) goto encoding_error; if(cp > 0x10ffff) goto encoding_error; if(pc32 != NULL) *pc32 = cp; if(cp == 0) return 0; else return nbytes; encoding_error: errno = EILSEQ; return (size_t)(-1); } size_t c32rtomb( char *restrict s, char32_t c32, mbstate_t *restrict ps ) { if(s == NULL) { *ps = (mbstate_t) {0}; return 0; } unsigned cp = c32; if(cp >= 0x10ffff) goto encoding_error; size_t nbytes = 4; if(cp < 0x10000) nbytes = 3; if(cp < 0x800) nbytes = 2; if(cp < 0x80) nbytes = 1; switch(nbytes) { case 1: { s[0] = cp; } break; case 2: { s[0] = 0xc0 | (cp >> 6); s[1] = 0x80 | ((cp >> 0) & 0x3f); } break; case 3: { s[0] = 0xe0 | (cp >> 12); s[1] = 0x80 | ((cp >> 6) & 0x3f); s[2] = 0x80 | ((cp >> 0) & 0x3f); } break; case 4: { s[0] = 0xf0 | (cp >> 18); s[1] = 0x80 | ((cp >> 12) & 0x3f); s[2] = 0x80 | ((cp >> 6) & 0x3f); s[3] = 0x80 | ((cp >> 0) & 0x3f); } break; } return nbytes; encoding_error: errno = EILSEQ; return (size_t)(-1); }