diff options
Diffstat (limited to 'vendor/nunicode/include/libnu/utf8_internal.h')
| -rw-r--r-- | vendor/nunicode/include/libnu/utf8_internal.h | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/vendor/nunicode/include/libnu/utf8_internal.h b/vendor/nunicode/include/libnu/utf8_internal.h new file mode 100644 index 0000000000..77b7eb5ced --- /dev/null +++ b/vendor/nunicode/include/libnu/utf8_internal.h @@ -0,0 +1,168 @@ +#ifndef NU_UTF8_INTERNAL_H +#define NU_UTF8_INTERNAL_H + +#include <sys/types.h> + +static inline +unsigned utf8_char_length(const char c) { + const unsigned char uc = c; + + if ((uc & 0x80) == 0) return 1; + if ((uc & 0xE0) == 0xC0) return 2; + if ((uc & 0xF0) == 0xE0) return 3; + if ((uc & 0xF8) == 0xF0) return 4; + + return 0; /* undefined */ +} + +static inline +void utf8_2b(const char *p, uint32_t *codepoint) { + const unsigned char *up = (const unsigned char *)(p); + + /* UTF-8: 110xxxxx 10xxxxxx + * |__ 1st unicode octet + * 110xxx00 << 6 -> 00000xxx 00000000 | + * -------- + * 110000xx << 6 -> 00000xxx xx000000 |__ 2nd unicode octet + * 10xxxxxx -> 00000xxx xxxxxxxx | + * -------- */ + *codepoint = (*(up) & 0x1C) << 6 + | ((*(up) & 0x03) << 6 | (*(up + 1) & 0x3F)); +} + +static inline +void utf8_3b(const char *p, uint32_t *codepoint) { + const unsigned char *up = (const unsigned char *)(p); + + /* UTF-8: 1110xxxx 10xxxxxx 10xxxxxx + * + * 1110xxxx << 12 -> xxxx0000 0000000 |__ 1st unicode octet + * 10xxxx00 << 6 -> xxxxxxxx 0000000 | + * -------- + * 100000xx << 6 -> xxxxxxxx xx00000 |__ 2nd unicode octet + * 10xxxxxx -> xxxxxxxx xxxxxxx | + * ------- */ + *codepoint = + ((*(up) & 0x0F) << 12 | (*(up + 1) & 0x3C) << 6) + | ((*(up + 1) & 0x03) << 6 | (*(up + 2) & 0x3F)); +} + +static inline +void utf8_4b(const char *p, uint32_t *codepoint) { + const unsigned char *up = (const unsigned char *)(p); + + /* UTF-8: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx + * + * 11110xxx << 18 -> 00xxx00 00000000 00000000 |__ 1st unicode octet + * 10xx0000 << 12 -> 00xxxxx 00000000 00000000 | + * ------- + * 1000xxxx << 12 -> 00xxxxx xxxx0000 00000000 |__ 2nd unicode octet + * 10xxxx00 << 6 -> 00xxxxx xxxxxxxx 00000000 | + * -------- + * 100000xx << 6 -> 00xxxxx xxxxxxxx xx000000 |__ 3rd unicode octet + * 10xxxxxx -> 00xxxxx xxxxxxxx xxxxxxxx | + * --------- */ + *codepoint = + ((*(up) & 0x07) << 18 | (*(up + 1) & 0x30) << 12) + | ((*(up + 1) & 0x0F) << 12 | (*(up + 2) & 0x3C) << 6) + | ((*(up + 2) & 0x03) << 6 | (*(up + 3) & 0x3F)); +} + +static inline +unsigned utf8_codepoint_length(uint32_t codepoint) { + if (codepoint < 128) return 1; + if (codepoint < 0x0800) return 2; + if (codepoint < 0x10000) return 3; + + return 4; /* de facto max length in UTF-8 */ +} + +static inline +void b2_utf8(uint32_t codepoint, char *p) { + unsigned char *up = (unsigned char *)(p); + + /* UNICODE: 00000xxx xxxxxxxx + * + * 00000xxx >> 6 -> 110xxx00 10000000 |__ 1st UTF-8 octet + * xxxxxxxx >> 6 -> 110xxxxx 10000000 | + * -------- + * |__ 2nd UTF-8 octet + * xxxxxxxx -> 110xxxxx 10xxxxxx | + * -------- */ + *(up) = (0xC0 | (codepoint & 0xFF00) >> 6 | (codepoint & 0xFF) >> 6); + *(up + 1) = (0x80 | (codepoint & 0x3F)); +} + +static inline +void b3_utf8(uint32_t codepoint, char *p) { + unsigned char *up = (unsigned char *)(p); + + /* UNICODE: xxxxxxxx xxxxxxxx + * |__ 1st UTF-8 octet + * xxxxxxxx >> 12 -> 1110xxxx 10000000 10000000 | + * -------- + * xxxxxxxx >> 6 -> 1110xxxx 10xxxx00 10000000 |__ 2nd UTF-8 octet + * xxxxxxxx >> 6 -> 1110xxxx 10xxxxxx 10000000 | + * -------- + * |__ 3rd UTF-8 octet + * xxxxxxxx -> 1110xxxx 10xxxxxx 10xxxxxx | + * -------- */ + *(up) = (0xE0 | (codepoint & 0xF000) >> 12); + *(up + 1) = (0x80 | (codepoint & 0x0F00) >> 6 | (codepoint & 0xC0) >> 6); + *(up + 2) = (0x80 | (codepoint & 0x3F)); +} + +static inline +void b4_utf8(uint32_t codepoint, char *p) { + unsigned char *up = (unsigned char *)(p); + + /* UNICODE: 000xxxxx xxxxxxxx xxxxxxxx + * |__ 1st UTF-8 octet + * 000xxxxx >> 18 -> 11110xxx 1000000 10000000 10000000 | + * -------- + * 000xxxxx >> 12 -> 11110xxx 10xx000 10000000 10000000 |__ 2nd UTF-8 octet + * xxxxxxxx >> 12 -> 11110xxx 10xxxxx 10000000 10000000 | + * ------- + * xxxxxxxx >> 6 -> 11110xxx 10xxxxx 10xxxxx0 10000000 |__ 3rd UTF-8 octet + * xxxxxxxx >> 6 -> 11110xxx 10xxxxx 10xxxxxx 10000000 | + * -------- + * |__ 4th UTF-8 octet + * xxxxxxxx -> 11110xxx 10xxxxx 10xxxxxx 10000000 | */ + *(up) = (0xF0 | ((codepoint & 0x1C0000) >> 18)); + *(up + 1) = (0x80 | (codepoint & 0x030000) >> 12 | (codepoint & 0x00E000) >> 12); + *(up + 2) = (0x80 | (codepoint & 0x001F00) >> 6 | (codepoint & 0x0000E0) >> 6); + *(up + 3) = (0x80 | (codepoint & 0x3F)); +} + +static inline +int utf8_validread_basic(const char *p, size_t max_len) { + const unsigned char *up = (const unsigned char *)(p); + + /* it should be 0xxxxxxx or 110xxxxx or 1110xxxx or 11110xxx + * latter should be followed by number of 10xxxxxx */ + + unsigned len = utf8_char_length(*p); + + /* codepoints longer than 6 bytes does not currently exist + * and not currently supported + * TODO: longer UTF-8 sequences support + */ + if (max_len < len) { + return 0; + } + + switch (len) { + case 1: return 1; /* one byte codepoint */ + case 2: return ((*(up + 1) & 0xC0) == 0x80 ? 2 : 0); + case 3: return ((*(up + 1) & 0xC0) == 0x80 + && (*(up + 2) & 0xC0) == 0x80 ? 3 : 0); + + case 4: return ((*(up + 1) & 0xC0) == 0x80 + && (*(up + 2) & 0xC0) == 0x80 + && (*(up + 3) & 0xC0) == 0x80 ? 4 : 0); + } + + return 0; +} + +#endif /* NU_UTF8_INTERNAL_H */ |